Hundreds of violent youths clashed with French police in a Strasbourg suburb on the eve of a NATO summit held here and in two nearby German cities.
Police said the youths, many of them masked, marched toward the city center in a spontaneous demonstration, demolishing bus stops, torching trash cans and attacking police with stones. A group of protesters also attacked a military vehicle, smashing a long pole through its windshield. A soldier inside drew his gun in response but didn't fire it.
Police responded with tear gas, officials said, eventually pushing back the youths, arresting roughly 200 of them.
Anti-NATO groups based in a camp a few miles outside Strasbourg condemned the violence.
"We strictly reject any form of violence against humans and objects," Reiner Braun, one of the leaders of the anti-NATO groups, said in a statement. "An escalation of violence in a militarized city full of police that is interested in provocations is useful only for proponents of war and armament."
U.S. President Barack Obama is due to arrive Friday in Strasbourg, where he will meet with French President Nicolas Sarkozy and German and French youths in a town-hall discussion. He then continues on to Baden-Baden, just across the border, where German Chancellor Angela Merkel welcomes NATO leaders with a festive dinner.
Protests in Baden-Baden, a health resort known for its lavish Roman-era bath houses, have been peaceful, with 300 people attending an anti-NATO event in Baden-Baden's heavily secured inner-city ring.
Roughly 15,000 police are securing events on the German side, with at least 10,000 French police stationed in Strasbourg.