1,000 Squatters Stage Riot in Eastern Berlin : Germany: Hundreds are injured in a battle that began when police evicted illegal tenants from three houses.

BERLIN —  Berlin suffered its worst street violence in a decade when more than 1,000 militant squatters fought a pitched battle with riot police overnight. Hundreds of people were injured.

The squatters, angered by the clearance of three occupied houses in east Berlin on Monday, pelted police with gasoline bombs, stones and metal bars, set fire to cars and a streetcar and dug deep trenches in the streets.

Outnumbered and forced to retreat at first, police fired tear gas and water cannons to contain the rioters, who fashioned barricades out of cars, garbage containers, building huts and barbed wire.

It was the latest episode in a rising spiral of violence since unification a month ago and raised questions about the social stability of the new German state.

“When young people in Germany try to use other means to point to problems, no one listens. When they use violence, the interest grows,” sociologist Wilhelm Heitmeyer told German television. “Politicians must not miss the warning signals.”

The Berlin city government came under criticism for provoking the violence.

“Some 135 injured police officers and untold plunder and destruction are the result of a flawed security policy by the Berlin political authorities,” the head of the German police union, Martin Gregg, said in a statement.

The riots could raise new objections among Germans to moving the government from Bonn to Berlin, a choice facing the pan-German Parliament to be elected next month.

Squatters have occupied about 100 houses in east Berlin since the fall of the Berlin Wall last November, protesting against a housing shortage and plans to raise rents heavily subsidized by the former Communist government.

A stringent element, including many from other parts of Germany and Europe, have occupied virtually an entire street in the run-down Friedrichshain quarter, where Monday night’s violence took place.

The quarter was calm by daybreak today, but burned-out cars and remains of the barricades closed the area to traffic.