The migrants, all men from Guinea, Nigeria and Senegal, were travelling on a boat with two Brazilians, the navy said in a statement.

It said that there was no immediate indication about the route they took but officials said that the boat was flying an Haitian flag. Local fishermen found the boat drifting off the town of Sao Jose de Ribamar, south of the Amazon river, on Saturday, the navy said.

They then towed it ashore and gave food and medicine to the occupants before they were processed by the police, the Maranhao human rights department said.

Brazilian officials said the group would be put into temporary housing by the state as the police investigate if crimes against them were committed in relation to their arrival in the country. Brazil is seen as an 'El Dorado' for international migrants, especially those from West Africa.