The U.N. mission, known by the acronym MINUSTAH, said the protesters were armed and fired on U.N. peacekeepers who fired back in self-defense, but it has opened an investigation into the Monday incident, CNN reported.
"The way in which the events unfolded leads to the belief that the incidents had a political motivation, aimed at creating a climate of insecurity on the eve of the elections," MINUSTAH said in a statement Tuesday.
"MINUSTAH calls on the population to remain vigilant and not let itself be manipulated by the enemies of stability and democracy in the country," the statement said.
The U.N. mission said one protester was killed in the riots in Hinche after being fired upon by a U.N. peacekeeper, while in Cap Haitien schools and banks were closed, residents set fire to tires at entrances to the town and there was gunfire in the streets, officials told CNN.
"We are facing the consequences of a cholera epidemic and in two weeks the elections, so the population is scared," Vincenzo Pugliese, a spokesman for MINUSTAH, said. "It's a volatile situation."
The demonstrations began after rumors spread that a Nepalese contingent of peacekeepers may have spread cholera, a Cap Haitien resident said.
"So they attack them," Marc George said. "The people were shooting."
A U.N. spokeswoman denied that its peacekeepers were responsible for the outbreak, CNN said.