(CN) - Protesters clashed with German police on the streets of Hamburg Thursday in advance of the Group of 20 summit opening tomorrow.
A spokesman for the police said officers used water cannons and pepper spray to disperse black-hooded protesters at the event dubbed "G-20: Welcome to Hell."
The official said masked protesters attacked the officers with bottles, stones and other objects and set fires in the street.
The fracas evidently started after authorities asked masked protesters -- a group the police described as "hardcore anti-capitalist demonstrators" -- to remove those masks.
They then decided to separate the group from the rest of the several thousand-strong demonstration and a melee ensued.
More than 100,000 protesters are expected in the city for the summit that takes place Friday and Saturday.
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