Athens (AFP) - A Greek far-left group has claimed responsibility for a gun attack on the Israeli embassy in December, a police source said Wednesday.

Anti-terrorist police found a text from the People's Fighter Group, contained in a memory stick left in a garbage bin, the source said.

A Greek newspaper had received an anonymous phone call on Tuesday pointing to the location of the text, whose contents have not been made public.

In the December 12 attack, a gunman riding on the back of a motorcycle raked the embassy with at least 54 rounds from a Kalashnikov rifle, police said. No-one was injured.

The police later matched the weapon to a similar attack by the group on the German ambassador's residence a year earlier.

Another two people on a second motorcycle were suspected of also taking part in the attack.

Embassies and diplomatic vehicles in Greece have been targeted by far-left groups in recent years.

The German ambassador's residence has been hit twice -- the 2013 incident and a rocket attack in 1999. No one was hurt.

In 2007, another rocket was fired at the US embassy in Athens without injuring anyone.

All three attacks were claimed by far-left groups, two of which have since been dismantled by the police.

But the People's Fighter Group remains active and its members at large.

The outfit has also hit the headquarters of the conservative New Democracy party in January 2013, when it was in power, and an auto dealership in January 2014, causing damage.