( dpa ) More than 10,000 people rallied in the Greek northern port city of Thessaloniki on Saturday to protest the poor state of the economy.
The demonstrators marched through the city just as Prime Minister Costas Karamanlis was giving an annual speech on the economy and badly needed economic reforms at the site of an international trade fair where 2,000 police where deployed to contain any potential violence.
A small group of demonstrators damaged a number of storefront windows and a bank, setting it ablaze with homemade gas cannisters while riot police retaliated by firing tear gas into the crowd.
Smaller clashes also broke out between two main rival protest groups.
Officials said a dozen demonstrators were arrested. Four people were slightly injured and taken to hospital.