Armed kidnappers seized an American missionary as he left his church near Haiti's capital and have demanded a ransom for his release, U.N. police said Monday.

Nathan Jean-Bieubonne, a U.S. citizen of Haitian descent, was snatched Sunday afternoon as he and three others drove home from church in Croix-de-Bouquets, a suburb of Port-au-Prince, U.N. police spokesman Fred Blaise said.

The kidnappers surrounded Jean-Bieubonne's all-terrain vehicle and forced him out at gunpoint while leaving the other three passengers, Blaise said.

"The men who kidnapped him are in touch with the family to demand the ransom," Blaise said, declining to discuss the amount.

Blaise said a U.N. anti-kidnapping task force was working with Haitian police to recover Jean-Bieubonne, whose hometown in the U.S. and church denomination were not immediately available.