The Czech-made twin-engine turboprop plane, operated by Tropical Airways, crashed shortly after take-off into a sugar-cane field which caught fire.
According to local radio reports, Sunday’s crash was caused by a door on the aircraft that had not been shut properly and opened after take-off.
Police said all passengers and one of the pilots were Haitian nationals, the other pilot was from neighbouring Dominican Republic.
Local television showed images of the destroyed plane and charred bodies. Police said the bodies were so badly burned it would be difficult to impossible to identify them.
The plane was travelling from Haiti's second largest city, Cap-Haitien, located 260 km north of the Haitian capital, to Port-de-Paix, in the northwest.
Tropical Airways owns several Let 410 UVP-E airplanes, purchased five years ago from Czech manufacturer Let AS.
They serve the route between Cap-Haitien and Port-de-Paix daily.
The Let 410 UVP-E is a twin-engine turbo-propeller plane that flies at 4,250 meters altitude. Its maximum capacity is nineteen passengers.