The Met Police said in a statement that "three men have been arrested following an attempted arson attack on the offices of a Persian language media organisation in north-west London".

Police said this "is not being treated as a terrorist incident but is being investigated by detectives from Counter Terrorism Policing London".

The Met Police linked the attack to two other arson incidents targeting ambulances and a Jewish charity and a synagogue, saying they are being treated as separate incidents but noting a "similarity" between the attacks.

A spokesman for the Persian-language TV station Iran International confirmed to AFP that it was the "organisation referred to in the Met statement".

The station condemned the attack, which it called part of a "sustained effort to intimidate Iran International and silence independent Persian-language journalism beyond Iran's borders".

Iran International is one of several Persian?language outlets critical of Iran's clerical leadership operating from abroad.

Housed in a heavily-secured building in west London, the newsroom employs about 200 journalists, with correspondents in Washington, Paris, Berlin and Tel Aviv and was labelled a "terrorist organisation" by Tehran in 2022.

Police said officers patrolling saw an "ignited container" thrown towards a building in Wembley, which landed in a car park and caused no damage.

Officers chased the suspects, who fled in a car that later crashed.

At that point, "a boy aged 16 and two men aged 19 and 21 were arrested on suspicion of arson endangering life and taken into police custody".

It followed threats against the station on Iranian state television and cyberattacks targeting journalists, the outlet's editorial board said.

Police revealed the incident after reporting an attempted arson attack on a synagogue, shortly after midnight on Wednesday in north London.

Attackers threw bottles suspected to contain petrol at the building in Finchley but caused no damage.

A 47-year-old woman and a 46-year-old man were later detained in Watford, north of the capital.

- 'Global instability' -

The little-known Harakat Ashab al-Yamin al-Islamiya (HAYI) group has claimed responsibility for the attack as well as for the incident at Iran International, SITE Intelligence Group reported.

The same group claimed to be behind the torching of a Jewish charity's ambulances in Golders Green in north London on March 23.

The Met Police's deputy assistant commissioner Vicki Evans told reporters the attacks came at a time of "global instability" when police saw "sustained and increasing aggressive and hostile activity on UK soil".

Police are "dealing with an unprecedented level of national security investigations, some with links to foreign states", Evans said.

Three people have been charged over the ambulance attack and police on Thursday announced new arrests of two 18-year-old men.