A group with possible links to the Iranian state is being investigated in relation to an arson attack on Jewish charity-owned ambulances, the head of the Metropolitan Police has said.

Four Hatzola ambulances were set ablaze in Golders Green, London, in the early hours of Monday, leading to several explosions caused by gas canisters onboard the vehicles.

Speaking at an event on Monday evening, Sir Mark Rowley said the "rapid growth" of Iranian state threats in recent years was grave but that it was still "too early" to attribute the attack to Tehran.

Police believe three suspects were involved in the attack, which is being treated as an antisemitic hate crime, not a terror incident.

Sir Mark said police were "pursuing all lines of enquiry", including "an online claim of responsibility by an Islamist group who have claimed other attacks across Europe and have potential Iranian state links".

He was speaking at an annual dinner of the Community Security Trust (CST), a charity that monitors antisemitism in the UK.

Iran-aligned group Harakat Ashab al-Yamin al-Islamiya - The Islamic Movement of the People of the Right Hand - made an unsubstantiated claim of responsibility for the attack on its Telegram channel.

Sir Mark also outlined additional security measures being put in place, which include 264 extra police officers being deployed to protect the Jewish community in London, alongside "additional highly visible firearms patrols".

Hatzola is a large non-profit, Jewish-led organisation that provides free emergency medical response and transportation to hospitals.

Run by volunteers, it has served the north London community of Golders Green, which has a large Jewish population, since 1979. There are dozens of synagogues throughout the area and according to the London Data Store, 49% of residents in the Golders Green ward identify as Jewish.

Ambulances belonging to a Jewish community charity in north-west London were set on fire on Monday.

The vehicles belonged to Hatzolah, a volunteer Jewish organisation that responds to medical emergencies.

After reviewing footage and taking witness statements, a force says its investigation is now closed.

A loaded gun, hydrochloric acid and an Islamic State flag were found in their car, prosecutors say.

Security had been increased at Jewish public institutions following an earlier incident in Rotterdam.