The New York Times, citing security officials in Port-au-Prince, said 17 Americans were abducted from a bus on Saturday.
They were leaving an orphanage and heading to the airport to drop off some of its members, Al-Jazeera reported.
The AFP news agency, also citing a security source, said the group is being held by an armed gang that for months has been engaged in theft and kidnappings in the area between Port-au-Prince and the border with the Dominican Republic.
In an audio message released by Haitian religious groups, members of these groups were asked to pray for the health of the 17 Americans.
No other details were immediately available.
Haiti is once again struggling with a spike in gang-related kidnappings that had diminished after President Jovenel Moise was fatally shot at his private residence on July 7, and following a magnitude 7.2 earthquake that struck southwest Haiti in August and killed more than 2,200 people.
RHM/PR