At least 15 people were taken off a bus after visiting an orphanage, Haitian security sources have told news media.
Few details are known, but US officials said they were aware of the reports.
Haiti has one of the highest rates of kidnapping in the world, as powerful gangs exploit the lawless situation to make money from ransom payments.
Since the killing of President Jovenel Moïse in July, rival factions have been trying to gain control and the lack of security has intensified the daily struggle to survive of many Haitians.
