Four people have been arrested on suspicion of spying for Iran on locations and individuals linked to the Jewish community in the London area, Scotland Yard has said.

The men – one Iranian and three dual British-Iranian nationals – were arrested on Friday at addresses in Barnet and Watford on suspicion of assisting a foreign intelligence service, namely Iran, the Metropolitan police said.

The police service said the investigation related to suspected surveillance of locations and individuals linked to the Jewish community in the London area.

Commander Helen Flanagan, the head of Counter Terrorism Policing London, which is leading the investigation, said: “Today’s arrests are part of a long-running investigation and part of our ongoing work to disrupt malign activity where we suspect it.

“We understand the public may be concerned, in particular the Jewish community, and as always, I would ask them to remain vigilant and if they see or hear anything that concerns them, then to contact us.”

The men were arrested at 1am on Friday in a pre-planned operation, the service said.

A 40-year-old man and a 55-year-old man were arrested at addresses in the Barnet area, a 52-year-old man was arrested at an address in Watford, and a 22-year-old man was arrested at an address in Harrow.

The Met said searches were ongoing at these locations and other addresses in Barnet and Wembley.

Six other men, aged 29, 39, 42, 49 and two aged 20, were arrested in Harrow on suspicion of assisting an offender. One of the men was further arrested on suspicion of assaulting a police officer.

All 10 men have been taken into custody, the Met said.