At least 74 migrants have died after the ship carrying them was wrecked off the coast of Libya, the UN says.

Rescuers managed to bring 47 survivors to shore, staff from its International Organisation for Migration (IOM) said.

Libya has been a major transit point for migrants from many countries trying to reach Europe via the Mediterranean.

The IOM says at least 900 people have drowned on this route this year, with another 11,000 returned to Libya, where it says they face detention and abuse.