Albanian police say they have arrested five opposition supporters for allegedly damaging ballot boxes and documents to prevent upcoming municipal elections.

A police statement also accuses the people arrested of physically attacking state police officers while storming election offices in the northern Albania city of Shkodra.

Clashes between supporters of opposition parties and police continued on Wednesday in about half a dozen municipalities. Albanian media outlets reported that at least five civilians and officers were injured.

The opposition is boycotting the local elections planned for June 30 and threatened to disrupt them. Albania's Socialist-led government insists the voting will go ahead as scheduled.