Athens  - Unknown assailants attacked a car dealership in Athens using petrol bombs and gas cannisters on Saturday, causing serious damage but no injuries in the latest spree of violence to rock the Greek capital.

Reports said a fire broke out at the site of the car dealership, destroying the building and more than five cars which were parked inside.

The attack occurred shortly after unknown assailants attacked a bank branch and police in the centre of Athens, slightly injuring an officer.

On Friday, a strong explosion shook Greece's main port of Pireaus, damaging nearby buildings but causing no injuries.

Greece has been plagued by daily bombings and arson attacks on banks and multinational businesses since the police shooting of a teenager in December, 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 has vowed to crack down on the increasing violence and has sought advice from Scotland Yard. (dpa)