At least nine people are dead and dozens more are missing after an overcrowded wooden boat went down off the south coast of Guinea.

The long thin pirogue boat had 69 passengers aboard when it left the port of Farmoriah for a weekly market further along the coast of the west African country, the national navigation agency said on Friday.

“It capsized at sea not far from (the market town of) Benty, leaving nine dead while 18 escaped,” the agency said in a statement read on television.

A local security source said the ill-fated ship was involved in a collision with another vessel at sea.

He confirmed nine people were dead and said 30 others remained unaccounted for.

The boat capsized minutes after leaving port, the source said, adding: “It slammed straight into a mining ship … and sank.”

The source said the mining ship belonged to the Forecariah Guinea Mining company, a joint venture set up by Australian Bellzone and the China International Fund (CIF) to mine iron ore.

The shipping accident happened off Forecariah province, already badly hit by the deadly Ebola virus which has spread in Guinea and neighbouring Liberia and Sierra Leone.