Anti-globalisation demonstrators have clashed with riot police in the German port city of Rostock ahead of a nearby G8 summit next week.

Around 100,000 protesters are expected in the city and 16,000 police officers are on duty in the lead up to the meeting - the country's biggest security operation since World War Two.

Retailers in the main commercial district have boarded up their shopfronts in anticipation of possible vandalism.