Counter-terror police are probing whether Iran ordered a series of arson attacks in London.
Scotland Yard also warned that it is dealing with an “unprecedented level of national security investigations with suspected links to foreign states, many of those with dangerous and often reckless intentions”.
Three people have now appeared in court charged in connection with an attempted firebombing on a Persian media company in north-west London on Wednesday. Oisin McGuinness, 21, Nathan Dunn, 19, and a 16-year-old boy appeared side by side in the dock at London’s Westminster Magistrates’ Court on Friday charged with arson with intent to endanger life.
In the early hours of Wednesday, there was an attempted arson attack at a synagogue in Finchley. A 47-year-old woman and a 46-year-old man were both arrested on suspicion of arson endangering life later that day.
Volunteer-led ambulances run by the Jewish community in Golders Green were set alight last month. On Thursday, officers arrested two 18-year-old men, one on suspicion of committing arson with intent to endanger life and the other on suspicion of conspiracy to commit arson with intent to endanger life. Three other people have already been charged in connection with the incident and another man was also previously arrested.
When asked whether Iranian-backed criminal proxies were behind the series of attacks, Vicki Evans, senior national coordinator for counter terrorism policing, said on Thursday: “We are open-minded and all lines inquiry are open at this stage.”
Due to the “nature and circumstances” of the three incidents, the Metropolitan Police said specialist detectives from counter-terror policing are now leading the investigation, although none have been declared as terrorist incidents. “Officers retain an open mind in respect of any motivation behind any of the attacks,” it added.
The force said that “the similarity with all three being arsons, and the nature of the buildings and locations”, has led to the decision for counter-terror police to investigate all three, although it is treating the incidents as separate.
This is despite an Iran-linked Islamist group having reportedly claimed responsibility for them all.
Harakat Ashab al-Yamin al-Islamia, which has claimed other attacks across Europe since the war in Iran broke out, posted videos on Telegram on Wednesday about the UK incidents, according to terror group monitor Site Intelligence.

Julian Lanches, from the International Centre for Counter-Terrorism, told the Financial Times the group was “unusual”.
The think-tank’s analysis showed the group had “no known references, neither online nor offline” before 9 March.
The group’s sudden appearance meant “there are considerable doubts that they are a genuine, serious terror group with offline or internal structures”, he added.
The Met said officers were aware of Harakat Ashab al-Yamin al-Islamia’s messaging.

Ms Evans said on Thursday: “These incidents have happened against an operational backdrop of global instability and sustained and increasingly aggressive hostile activity on UK soil.
“Whilst these investigations are ongoing and we’re progressing multiple lines of enquiry, I understand why our communities here in the UK will be concerned to learn of these arson attacks.
“We are now dealing with an unprecedented level of national security investigations with suspected links to foreign states, many of those with dangerous and often reckless intentions.
“I want to reassure our communities that Counter Terrorism Policing will be relentless in tracing those responsible for these acts of violence on our streets.
“If you are part of this activity, then know that you will be caught, and you will face justice.
“Anyone with information about any of the incidents this week, please speak to the police.”
Police are asking the public to remain vigilant and to contact police if they are concerned by calling police on 0800 789 321 or visiting www.gov.uk/ACT