Three thousand police fired tear gas and water cannons Wednesday during a successful five-hour battle to drive hundreds of leftist radicals from a dozen rundown tenements in eastern Berlin.

Police and a special paramilitary unit used armored personnel carriers and bulldozers to break down barricades erected by the leftists. Hundreds of squatters living on Mainzer Strasse responded with firebombs and rocks.It was the third consecutive day of clashes on the street this week.

ZDF television said several police officers were injured, but there was no immediate word on injuries among the squatters. ZDF said 135 people were arrested.

Police raided Mainzer Strasse and adjoining blocks at 7 a.m. and battled for control for about five hours before driving the squatters from the ramshackle tenements splashed with slogans and signs, including "Eat the rich."

Berlin Interior Minister Erich Paetzold said Wednesday's clash was marked by "unbelievable brutality" from the radicals.

Late Monday night and Tuesday morning, leftists battled with police for nearly 10 hours on Mainzer Strasse. About 137 police were injured and 20 people were arrested in those clashes.

Fighting began Monday on Mainzer Strasse after police began evicting leftist radicals from houses in other parts of the city. The leftists say they have a right to the abandoned homes and have mobilized their supporters to resist police action.

Police spokesman Werner Thronicker said Mainzer Strasse is headquarters for people responsible for "serious criminal acts."

Anarchists from the former West Berlin have taken over about 12 tenement buildings on the block in recent months and several houses elsewhere in eastern Berlin.

While East Germany's democratic government did little to evict the squatters, officials have begun cracking down since German unification Oct. 3.

The clashes have drawn new attention to the shortage of affordable housing in Berlin and other German cities. The situation is expected to be particularly acute in eastern Berlin, where many residents still pay relatively low rents.

Under the former communist system, rents were heavily subsidized by the government. They are to begin rising in January.