He reportedly told his guards on the vessel to shoot anyone who refused.

The BBC's Cathy Jenkins says it is often very difficult to get independent confirmation of such incidents, which have happened before.

But she adds that in this case news of the incident came from fishermen who picked up survivors.

Gunshot wounds

Witnesses said some of the passengers - thought to number about 160 - were fleeing civil strife in Somalia, while others were trying to reach Yemen from where they would head to Saudi Arabia to seek work.

The elders - contacted by radio at Laskoray in the Sanag region - said some of the dead had been shot after they refused to obey the crew's instructions to jump overboard after the engine failed, AFP reported.

The whereabouts of the captain and crew remain unknown.

Since civil war broke out in Somalia in 1991, thousands of people have tried to flee to Yemen to escape the fighting and to look for work.

Bossaso is in Puntland, a region of Somalia which has declared itself autonomous.

The authorities there have tried to stop the flow of refugees, but, as our correspondent notes, the business has proved too lucrative to halt.