Greece's New Democracy Party HQ Shot at

No injuries reported

Unidentified attackers opened fire on the Athens headquarters of Greece's governing New Democracy party with a Kalashnikov assault rifle early on Monday, in what the government said was a worrying escalation in political violence.

Police said a bullet pierced the window of the office that the conservative prime minister, Antonis Samaras, maintains in the building near the city centre, but no one was hurt.

The early morning gun assault follows a spate of makeshift bomb attacks against journalists and political figures in the past week, some claimed by leftist groups angry at Greece's deep financial crisis.