Hundreds of thousands of Europeans peacefully rallied against their governments' handling of the economic crisis during May Day, but Berlin experienced the worst rioting in years.

France saw 300 peaceful labor union demonstrations all over the country, with the number of people marching to show their frustration over rising unemployment caused by the global economic crisis estimated by police at 450,000. (Unions said 1.5 million people marched.)

But while protests remained peaceful in France, a country used to large-scale demonstrations, demonstrators clashed with police in Turkey and Greece.

In Istanbul, police used water cannons and tear gas to stop protesters from converging into the city center; in Greece, police clashed with far-left anarchists near an Athens university.

Some of the heaviest fighting, however, took place in Germany.

The streets around the Kottbusser Tor subway station in Berlin's Kreuzberg district resembled a battlefield shortly before midnight on May 1, Europe's labor day holiday. People were meandering through a sea of broken glass and black, burned-out trash cans. Large holes dotted the sidewalks as rioters had forced the pavement open in order to load up on stones to pelt police with. They also threw firebombs and broken beer bottles; police responded with tear gas and batons.

The rioting, which started around 7 p.m. Friday and lasted for several hours, was the worst in years, observers said. It pitted some 5,800 police against an estimated 2,500 rioters, with officials on Sunday reporting 289 arrests and 273 police injured.

"In our efforts to have a peaceful May Day, we have suffered a setback," said Berlin's Interior Minister Ehrhart Koerting, who with other officials had warned of the far left's increased readiness to violently disrupt May Day demonstrations.

Just a few hundred yards from the rioting, tens of thousands of people had celebrated a peaceful community party, with the smell of homemade kebab filling the air and people listening and dancing to live music.

"There are people out in the streets protesting peacefully against the economic crisis, and there is nothing wrong with that," a Berlin police spokesman said. "But when people burn cars and trash containers … it has nothing to do with political protests."

On Monday, observers criticized the police strategy, which was banking on appeasement, as too mild to contain the fighting. They called for water cannons to return to the streets next year to get tough on the mostly black-clad youths who are not interested in sharing their political views but rather in brawling with police.

Forty-four arrest warrants have been issued so far, with four rioters still in jail facing attempted murder charges, as they are suspected of having throwing firebombs at police, officials said. In other incidents, rioters tried to torch police by pouring flammable liquids over them and lighting them with a match. Thanks to quick help from colleagues, the police were not injured. "But it's only a matter of time before someone gets killed," said Konrad Freiberg, the head of Germany's police union.

A neo-Nazi demonstration with a few hundred participants in Dortmund, western Germany, also turned violent. Elsewhere in the country, peaceful demonstrations drew nearly 500,000 participants, Germany's unions said.