Tensions are high in Albania as voters prepare to cast ballots in local elections Sunday, following an election season that has been marred by violence.

The latest incident took place Thursday. Police say a car bomb exploded near the northern town of Kukes, damaging the vehicle of a Socialist opposition candidate running in Sunday's election. Investigators say no one was seriously wounded in the incident.

In January, anti-government riots left four people dead and many others injured.

The Balkan country has become deeply polarized between the governing Democratic Party and the opposition Socialists. The unrest is affecting the country's efforts to become part of the European Union. The EU has required Albania to fight corruption and organized crime, improve its human rights record and carry out extensive public reforms before it can be considered for EU membership.

Voters will choose mayors, heads of local governments and council members in Sunday's polling.