Four men were arrested in areas north of London on suspicion of assisting Iran’s intelligence service by spying on locations and individuals linked to the Jewish community. Counterterrorism police said the arrests were part of a preplanned operation tied to a long-running investigation into suspected foreign interference.

The suspects, including one Iranian national and three dual British-Iranian nationals, were detained under the National Security Act. Searches were carried out at multiple properties in Barnet, Watford, Harrow and Wembley. Six additional men were arrested on suspicion of assisting one of the primary suspects.

Authorities said there has been no change to the national terror threat level, which remains at substantial, meaning an attack is considered probable. Officials emphasized ongoing vigilance amid concerns about Iran’s activities in Britain, which intelligence services have previously identified as a significant security threat.