ATHENS (Reuters) - Attackers threw a hand grenade at a Greek police station on Monday morning, injuring a bystander, police officials said.

The grenade was thrown about 50 meters away from a police station in an Athens suburb during heavy rain and was not immediately noticed by police, one of the officials said.

Authorities started investigating after a taxi driver reported the incident.

He had pulled over to fix his vehicle, heard a “pop” and saw wounds on his feet that he initially thought had been caused by fragments of a faulty headlight which exploded, police said.

A few hours later, a group that did not identify itself uploaded a brief statement on a website often used by anarchist, anti-establishment and leftist activists saying it had thrown the grenade in the area.

Police said they were investigating the claim of responsibility.

The windows and doors of some cars parked near the police station were also damaged by hand grenade fragments, another police official said.

Small-scale attacks on businesses, state buildings, police and politicians are frequent in Greece, which is has a long history of political violence and is emerging from a debt crisis that has forced it to slash wages and pensions.

The group said that Monday’s act was in support of a 29-year old man in detention, suspected of involvement in a booby-trapped parcel attack that injured former prime minister Lucas Papademos last year.