Protesters have clashed with police at a largely peaceful anti-globalization rally in the German city of Rostock.

Rocks, bottles and sticks have been hurled at riot police, who are using tear gas and batons charges to try to disperse the hundreds of rioters.

However, the violence only involves a small portion of the estimated 30,000 people police say had joined the rally.

They are protesting against next week's G8 summit of leading industrial nations in Heiligendamm, 25km (16 miles) away.

More than 160 groups of anti-globalization activists, left-wing groups, students and anarchists had been taking part in the march.