Fifteen children have been killed in a fire at an unlicensed orphanage outside Haiti's capital Port-au-Prince.

The building, which had not been authorized to operate as an orphanage since 2013, housed about 66 children, said local judge Raymonde Jean Antoine.

The fire began shortly after 9:00pm Thursday (0200 GMT Friday), she said.

Two children died in the blaze and 13 others died at a local hospital as a result of smoke inhalation, the judge added.

The cause of the fire and the victims' ages were not immediately known.

The two-story building was in a state of complete disrepair, with bunk beds crammed into small rooms, a cramped staircase and only one usable exit door, according to an AFP reporter.