It comes after after another attempted arson attack at a north-west London synagogue.
Counter-terror police are looking into whether the series of arson attacks against Jewish sites in north London have been carried out by Iranian proxies.
It comes after officers on “deterrence and reassurance patrols” in the wake of the previous incidents spotted damage to a window of Kenton United Synagogue, Harrow, at around midnight on Sunday.
Vicki Evans, Deputy Assistant Commissioner of the Metropolitan Police, said the incidents have been “similar in nature”, targeting Israeli and Jewish premises within London.
Ms Evans said most have been claimed online by Harakat Ashab al-Yamin al-Islamia, the Islamic Movement of the Companions of the Right.
The same group has recently claimed attacks across Europe, including at Jewish and Israeli premises, Ms Evans said.
She went on: “I want to be clear, irrespective of the motivation of this group, to those who are facilitating this activity on their behalf and those who are committing the acts, we will not tolerate activity that seeks to intimidate and harm our communities, you will not succeed in creating division and hate.
“As the conflict in the Middle East continues to evolve, counter-terrorism policing and our partners remain alive to the threat of Iranian hostile activity in the UK.
“We are aware of public reporting that suggests this group may have links to Iran – as you would expect we will continue to explore that question as our investigation evolves.”
