The Israeli embassy in London was the target of a terror plot linked to Iran, it has emerged.
A group of Iranian men are feared to have been planning an atrocity at the embassy in Kensington.
Special Forces troops joined counter-terrorism police in raids at the weekend amid fears an attack was imminent.
Dramatic video footage showed one of the suspects being led from a house in Rochdale and bundled to the ground by heavily-armed police officers.
Scotland Yard has refused to confirm the target of the alleged terror plot.
Home Office minister Dan Jarvis urged MPs “not to speculate” on the location targeted by a suspected terror plot, as he gave a statement on two separate counter-terrorism investigations that both involved Iranian nationals.
Mr Jarvis told the Commons: “The two operations that took place across multiple locations this weekend were significant and complex. They were some of the largest counter-state threats and counter-terrorism actions that we have seen in recent times.”
He added: “In total, eight men were arrested by the Metropolitan Police’s Counter-Terrorism Command. Five men were arrested on suspicion of preparation of a terrorist act, contrary to section 5 of the Terrorism Act of 2006 as part of a proactive investigation in the areas of west London, Swindon, Rochdale, Stockport and Manchester.
“All five men are Iranian nationals. Whilst four of the individuals remain in police custody, the fifth individual has now been bailed with strict conditions.
“As part of the investigation, police officers carried out searches at a number of addresses in the Greater Manchester, London and Swindon areas. Investigations continue with searches and activity still under way at multiple addresses across the country.
“The investigation relates to a suspected plot to target specific premises. Police officers have been in contact with the affected site to make them aware and provide relevant security advice and support.
“However, the police have also been clear that for reasons of operational security and public safety, they are not and I am not able to provide further information on the target at this time, and I would urge members not to speculate on the site.”
Security minister Dan Jarvis has declined to reveal the immigration status of the Iranian nationals arrested on Saturday.
Conservative former minister Sir Edward Leigh asked in the Commons: “Do we know whether these men entered the country illegally or legally? Obviously people who enter this country legally are subject to extraordinarily sophisticated surveillance at our airports and ports, but people who enter illegally there’s no surveillance at all.
It’s complete madness that thousands are entering our country with no checks at all.
“Isn’t this a good opportunity to seek a derogation from the Court of Human Rights in Strasbourg and say, because of our national security, we should have the right to detain these people, arrest them and rapidly deport them?”
Mr Jarvis replied: “There are very strict limitations on what ministers can say at this point because it would be unforgivable, frankly, to cut across a live counter-terrorism investigation.
“The police have set out the Iranian nationality of those arrested, and at this particular moment they need the time to pursue various lines of inquiry and investigation… as a consequence of that, it would be wrong for ministers to provide a running commentary on individuals’ details at this stage because, as members would expect, a wide range of security assessments are under way.”
Mr Jarvis said Home Secretary Yvette Cooper “will set out further details at an appropriate moment in due course”, although Reform UK deputy leader Richard Tice later noted: “In order to prevent misinformation, surely the minister should tell us and the British people who want to know how long have these Iranian nationals been in this country and what is their immigration status?”
This is a breaking story. More to follow.