CNN reported residents and officials told the U.S. news network the situation in Cap Haitien had devolved into random gunfire and the torching of a police station and tires at the town's entrances. Schools and banks were closed.
Vincenzo Pugliese, a spokesman for the U.N. stabilization mission in Haiti, said demonstrations got out of hand in two separate locations, necessitating the use of anti-riot police.
"Apparently, some people were injured by bottles or stones," he said. "We are facing the consequences of a cholera epidemic and in two weeks the elections, so the population is scared. It's a volatile situation."
Cap Haitien resident Marc George told CNN by telephone that people were fighting the U.N. peacekeepers.
"It's not safe to walk in the streets," George was quoted as saying. "The people were shooting."
The demonstrators were agitated by rumors that a Nepalese contingent of peacekeepers may have been responsible for spreading the cholera, he said. "So they attack them," he said.
A U.N. spokeswoman denied the peacekeepers were responsible for the outbreak.
Pugliese said there also were about 400 protesters in the town of Hinche where clashes left a half-dozen peacekeepers injured.
More than 900 people have died and nearly 15,000 hospitalized since the outbreak started.