Greek police say a small bomb has exploded outside the office of a governing Socialist lawmaker in Athens, causing minor damage and no injuries.

Police say the device, which was made of camping gas canisters, had been placed at the entrance to Nasos Alevras' office in the center of the capital.

There has been no claim of responsibility for Friday's attack.

Greek anarchist groups frequently firebomb symbols of wealth and authority. The attacks have intensified after last year's fatal police shooting of a teenager in central Athens, which sparked several days of violent protests.