Counter-terrorism policing chief Laurence Taylor called on people to remain vigilant after what he described as "an elevated threat to Jewish and Israeli individuals and institutions in the UK" after the attack in Golders Green.
Golders Green attack - follow latest
Speaking on Thursday, Mr Taylor said the country had seen a "gradual increase in terrorist threats for some time", which he claims has been "driven by a rise in both Islamist and extreme right-wing terrorism".
The UK's terror threat level has been raised from "substantial" to "severe" for the first time in five years.
A severe threat level – the second highest of five terrorism threat levels – means an attack is considered highly likely in the next six months.
Read more: How the UK's terror threat level works
Police have arrested Essa Suleiman, a 45-year-old British national born in Somalia, on suspicion of attempted murder after two men – Shilome Rand, 34, and Moshe Shine, 76 – were taken to hospital with stab wounds in what authorities have declared a terror incident.
Mr Rand, who has since been discharged, told Sky News home editor Jason Farrell the prime minister must "take charge" and do more to keep Jewish communities safe, given the string of attacks in recent months.
Sky News has also learned the Golders Green suspect was jailed over the stabbing of a policeman and his dog in Swindon in 2008.
Iran denies involvement in attacks on British Jews
Iran's embassy in the UK has said it "categorically rejects" allegations Tehran was involved in "violent activities or incidents in the United Kingdom".
In a statement on Thursday, the embassy described such claims as "baseless accusations" that "lack credible evidence and appear to serve narrow political agendas".
It also claimed it had previously raised concerns with UK authorities about possible "false flag" operations – typically defined as an act that can be blamed on an adversary to justify retaliation.
The embassy's remarks follow comments made by Sir Keir Starmer - who was heckled during his visit to Golders Green - insisting that the government needs "stronger powers to tackle the malign threat posed by states like Iran" that want to "harm British Jews".
Read more from Sky News:
Teens jailed after killing man they believed was a paedophile
The war in Iran is coming for Britain's favourite food
Counter-terror police have been looking into the possible involvement of Iranian proxies after a spate of recent attacks on Jewish sites in London, with Mr Taylor claiming officers are working against "threats by state-linked actors".
The incidents include a number of arson attacks appearing to target Jewish buildings and premises, which the Metropolitan Police's deputy assistant commissioner Vicki Evans said have been "similar in nature".
However, Home Secretary Shabana Mahmood said it was too early to know whether the perpetrator of Wednesday's Golders Green stabbing could have links to Iran.
The Met is also reviewing whether upcoming pro-Palestine marches should be banned. The Stop the War Coalition is planning a major demonstration in London on May 16 to mark Nakba Day, commemorating the 1948 displacement of Palestinians during the creation of Israel.
The group has described attempts to link recent attacks with marches as "false".
They were the words of the Bank of England's governor on Thursday while warning over the risks posed to the UK economy by the surge in global energy costs.
It does not bode well for the nation's favourite food: chips.
But a leading figure in the potato industry has told Sky News we won't see the worst until next year.
Scott Walker, the chief executive of GB Potatoes, said the way the industry works means the impact of war-linked costs will be delayed, with "inevitable" increases in 2027.
He was speaking amid government warnings of more than eight months of rising prices once the conflict in the Middle East ends, while the fish and chip shop industry sees an immediate threat to its very existence.
Rising costs for energy, cooking oil and fish are already being reflected in portion sizes or prices, according to the National Federation of Fish Fryers, which fears an acceleration in this decade's trend of shop closures.
When it comes to the humble spud, the cost of the base potato product actually remains weak due to a continuing, Europe-wide glut, according to Mr Walker, though chip shop prices could rise to help account for the extra price pressures already facing fryers themselves.
Follow the latest on the Iran war
Mr Walker explained that the vast majority of UK potato producers work to annual growing contracts with their customers, which give both growers and the likes of wholesalers and supermarkets "insurance" – a certainty over incomes and prices ahead.
"At this moment in time, people shouldn't be paying any more," he said, in good news for buyers of the many raw potato varieties in the shops.
Fertiliser, for example, was already bought for the current growing year ahead of the outbreak of the war, but Mr Walker said the outlook was more bleak.
"Down the line prices will have to rise because we have a lot of costs coming," he warned.
While growers could attempt to claim "exceptional" costs from their customers in a bid to restore some health to margins this year, Mr Walker warned the 2027 contracts would have to reflect a doubling of red diesel and some fertiliser prices.
He also highlighted higher plastic packaging charges, along with raised tax and wage demands imposed by the government.
"The average price was about 65p (a litre) for red diesel last year," he explained.
"Farmers this year have been paying about 140p, but it has dipped back to around 120p."
Mr Walker warned that much would also depend on the weather in the months ahead, with a dry summer forcing farmers to irrigate more using diesel-powered generators.
"If diesel prices remain high, that's going to be a big extra cost," he warned, signalling that planting, irrigation, harvesting and distribution costs were all flashing red.
"Sadly, rising prices are inevitable... Everyone faces rising prices: the cost of collection, living wage, (the) price of electricity for wholesalers. There's a lot of cost in the system."
What about crisps?
Mike Russell Smith, who co-founded the Savoursmiths luxury crisp brand outside Cambridge in 2016 alongside his wife, grows his own potatoes and manufactures the product on site.
He echoed Mr Walker's sentiments over the surge in costs.
He explained that a "massive oversupply" across Europe last year, due to strong crop yields, had depressed prices, but the business, at the same time, was already grappling with a doubling of sunflower oil costs due to the effects of the Russia-Ukraine war.
He pointed to rising costs for labour, harvesting, production and cold storage.
"The softer price of the potato due to the surplus of supply is going to be significantly offset by considerably higher prices in terms of energy, gas, electricity and the sunflower oil we cook the potatoes in," he explained.
On the prospect of price increases for consumers, he added: "In 2027, we'll certainly have to review things in what is a very competitive industry. There comes a point where the costs just aren't swallowable anymore."
The industry 'plea'
Mr Walker argued it was in the gift of government to help ease the burden facing the industry.
He said: "Most of it is out of our hands. The plea to government...unfortunately is a lot of the rules and regulations are adding to the burden, and we call on the government to ease those regulations and help with electricity costs.
"Access to water is a key thing for growing potatoes, so we keep asking for regulation to allow farmers to store water to secure food security."
A government spokesperson said in response: "We are taking the effects of the Iran war very seriously and are actively monitoring the potential impact of the conflict on the food and farming sector.
"The UK has a resilient food system, and at present we do not expect any impact on availability. We are continuing to meet with stakeholders, including farmers' unions, to share information on rising fuel and oil prices."
Speaking to Sky's Electoral Dysfunction podcast, Harriet Harman said it makes ministers "feel very demotivated and anxious", and it "undermines morale and perception".
The criticism of Number 10's media handling comes after our political editor Beth Rigby revealed that Sir Keir Starmer's inner team is split over whether a reshuffle should take place after the elections on 7 May.
She was told by senior government sources that the prime minister's acting chief of staff Vidhya Alakeson and key cabinet figure Darren Jones, secretary to the prime minister, are advising Sir Keir to pause on a reshuffle.
On the other side, political director Amy Richards and chief whip Johnny Reynolds are pushing for one.
Downing Street did not shut down reports this week that changes to the prime minister's top team could be incoming, simply telling journalists that they do not comment on "speculation".
Baroness Harman criticised that, telling the Electoral Dysfunction podcast: "I just feel a bit dispirited because I feel it's unwise for Number 10 to have put into the public domain the idea that if there's a bad election result on 7 May, the solution is going to be a reshuffle.
"Firstly, because if he [Starmer] decides that he doesn't want to do a reshuffle after 7 May, because of all the speculation that has been running that there's going to be one, it will look as if he hasn't done a reshuffle because he wanted to, but he's just not strong enough."
Reshuffle talk also "makes secretaries of state and ministers feel insecure", pointing to reporting that the technology secretary, Liz Kendall, could be among those to go.
"She's going to feel very demotivated and anxious," said Baroness Harman.
"But also her diary secretary's going to think, 'why should I bust a gut to get all these appointments in her diary for the second half of May or June? Because she's probably not going to be in her job.'"
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'It undermines morale'
She went on to explain that outside organisations planning meetings or conferences with Ms Kendall, or other ministers facing the chop, could "hold fire" because someone else might be in the job.
Baroness Harman added: "It's unwise, even if they were planning to do a reshuffle and were absolutely certain on it, but it's even more unwise if it's actually not yet decided.
"So this is another handling issue – it undermines morale and perception."
Starmer in 'precarious position'
Beth Rigby explained on the podcast how she learnt on Wednesday of the discussions in Downing Street about a potential cabinet reshuffle.
The split in the prime minister's team, she said, "tells you a lot" about his position.
It's a "high stakes" moment for the government, Rigby said, adding: "The fact we've been talking about this is a reflection of the precarious predicament… the prime minister is in."
Washington attorney Jeanine Pirro posted the footage on her X page.
It appears to show suspect Cole Allen, 31, scoping out the venue and charging through a screening checkpoint with a raised firearm as a secret service agent opens fire.
Authorities say the agent – one of around a dozen federal officers at the checkpoint when the gunman emerges from a doorway down the corridor – fired five times after Allen pointed his gun at them.
The agent is the only one who appears to draw their weapon before Allen goes through the screening equipment.
Allen was injured but not shot during Saturday night's incident, but one agent was shot in a bullet-resistant vest. It was unclear whether they were shot by Allen or an agent, but Ms Pirro said there was no evidence of friendly fire.
Still images of the suspect on the night of the attack – which targeted one of Washington's highest-profile events of the year – were released earlier this week as part of a court filing by the Department of Justice.
They showed Allen taking selfies with weapons, which prosecutors say included a sheathed knife, shoulder holster and bag filled with ammo.
The photos were taken at around 8.03pm local time, around half an hour before the moment in the footage where Allen rushed through the screening checkpoint.
He's been charged with one count of attempted assassination of Mr Trump, interstate transportation of a firearm and ammunition with intent to commit a felony and discharge of a firearm during a violent crime.
Read more from Sky News:
UK terror threat level raised
War comes for Britain's favourite food
The filing also claims he tracked the president's and Melania Trump's movements via websites and live coverage from media companies of the event, held at the Washington Hilton.
The couple and other senior officials were quickly evacuated from the event after several gunshots were heard.
Assistant US attorney Charles Jones wrote in the filing: "Had the defendant achieved his intended outcome, he would have brought about one of the darkest days in American history."
Allen, a part-time tutor and amateur video game developer from California, will remain in prison while he awaits trial, having not entered a plea during a brief court appearance.
Temperatures could reach 27C (80.6F) in London and East Anglia on Friday, the Met Office said, making it the warmest day of the year so far and hotter than Honolulu, Hawaii's capital, where highs of 26C are forecast.
Friday's highs will be around 10C (50F) higher than the average for this time of year, which is between 15C (59F) and 17C (62.6F), the Met Office said.
Cardiff, meanwhile, could be warmer than Athens, with forecasters predicting temperatures could reach 19C (66.2F) in the Welsh capital.
Find out the forecast for your area
However, the warm weather falls short of the record UK high in April, which was 29.4C (84.9F) recorded in central London in 1949.
Met Office meteorologist Simon Partridge told the Press Association: "We've got some very warm, humid air coming up from the south.
"That means we will see some very warm weather, particularly in the east and the South East, because there we'll see the best of the sunshine."
However, Mr Partridge warned that it "doesn't mean everybody's going to get a warm, dry, beautiful day".
The central spine of the UK – in parts of Scotland, the Pennines and the Midlands – could see some heavy rain and thunder.
The Met Office also warned the weather over the bank holiday weekend will be "a different story", with bright spells and showers expected on Saturday and rain forecast for most of the country on Sunday.
Read more from Sky News:
Public urged to 'be alert' as terror threat raised
The war in Iran is coming for Britain's favourite food
Mr Partridge said: "By the time we get to Monday, we're actually going to see temperatures roughly where they should be for this time of year.
He said temperatures would likely be around 11C (51.8F) to 12C (53.6F) in the north, with the south expected to experience temperatures of up to 16C (60.8F).
"So it will feel quite fresh and chilly compared to what we've had," Mr Partridge added.