Athens - A strong explosion rocked the southern suburb of Athens Tuesday after unknown assailants set off a bomb at a bank branch, causing severe damages but no injuries, reports said.

Reports said the pre-dawn attack against the branch of Eurobank in the southern of Agrigroupoli startled residents who ran out of their homes in panic.

Police said the unknown assailants had used 20 kilos of explosives planted in a suitcase at the entrance of the bank. Nearby cars and building suffered extensive damage from the explosion.

Bomb experts were notified of the attack after an anonymous call was placed to a local police station and the Greek daily newspaper Eleftherotypia.

According to reports, bomb experts had arrived at the scene of the attack just as four hooded individuals were fleeing the bank on motorcycles, threatening police at gun-point to back off.

Greece has been plagued by daily bombings and arson attacks on banks and multinational businesses since the police shooting of a teenager in December 2008, which sparked the worst riots the country has seen in decades.

The violence has embarrassed Prime Minister Costas Karamanlis' government, which has been criticized for its inability to protect citizens.

The government vowed to crack down on the increasing violence and has sought advice from Scotland Yard. (dpa)