MSF said its Geo Barents search and rescue vessel picked up 146 migrants in two operations and then found a further 20 in a separate boat.

However, they also plucked the bodies of 11 people who were seen by a spotter plane floating in the sea.

"We do not know the precise cause of this tragedy, but we know that people continue to die in a desperate attempt to reach safety. This slaughter must end," MSF said on the social media platform X.

The Sea Watch group, whose plane saw the bodies, said they tried to contact Libya's coast guard to go and retrieve the dead, but received no reply. "This is what happens in the Mediterranean, even when nobody sees it," it said in a statement.

--Reuters--