Greek police say they have arrested four foreigners and seized weapons and explosives in a raid by the country's anti-terrorist unit on residences in the greater Athens area.

Police said an operation by the anti-terrorist unit that began Monday morning was continuing into the afternoon. They did not specify the quantities or types of weapons, or release the nationalities of those detained. Greek media said they appeared to be Turkish nationals suspected of belonging to the Revolutionary People's Liberation Party-Front, or DHKP/C.

Authorities said they would be releasing further information on the raid later in the day.