Eleven migrants died and 64 were missing on Monday after two shipwrecks off southern Italy, according to a German charity, the Italian coast guard and United Nations agencies.

The German aid group RESQSHIP, which operates the Nadir rescue ship, said it picked up 51 people from a sinking wooden boat, including two who were unconscious, and found 10 bodies trapped in the lower deck of the vessel.

"Our thoughts are with their families. We are angry and sad," it wrote on X.

RESQSHIP said the survivors were handed over to the Italian coast guard and taken ashore on Monday morning, while the Nadir was making its way to the island of Lampedusa, towing the wooden boat with the bodies of the deceased.

The UN Refugee agency UNHCR, the International Organization for Migration (IOM) and UN children's agency UNICEF said in a joint statement that the migrants intercepted by the German charity came from Syria, Egypt, Pakistan and Bangladesh.

The second shipwreck took place about 200 km (125 miles) east of the Italian region of Calabria, as a boat that had set off from Turkey eight days earlier caught fire and overturned, the UN agencies said.

They said 64 people were missing at sea, while 11 were rescued and taken ashore to the Calabrian town of Roccella Ionica by the Italian coast guard, along with the body of a woman.

The coast guard earlier said it was looking for an unspecified number of missing migrants, with the help of the EU border agency Frontex.

The migrants' vessel, a sailing boat found partially sunk, was first spotted by a French boat in international waters where Italian and Greek search and rescue zones overlap, the coast guard said.

The UN agencies said the migrants involved in the second shipwreck came from Iran, Syria and Iraq.

They again called on EU governments to step up Mediterranean search and rescue efforts and expand legal and safe migration channels, so that migrants "are not forced to risk their lives at sea".

According to the IOM, more than 23,500 migrants, including 749 in the year to date, have died or gone missing in the central Mediterranean since 2014, making it one the world's most dangerous migration routes.

Earlier this month 11 bodies were recovered from the sea off the coast of Libya.