Nearly 7,000 migrants have been returned to Libya since January 2020
UN criticises the “sharp reduction” in efforts by European countries to carry out search and rescue operations.
Spanish authorities have found a boat near the Canary Islands with 10 dead migrants on board, while another 45 have perished in a shipwreck off the Libyan coast.
A plane spotted the first vessel while searching for a missing boat that had left Mauritania on 15 August with about 40 people on board and was believed to be heading to the Spanish islands off north-west Africa.
Two Spanish Maritime Rescue Service vessels reached the shipwreck about 85 miles south of the island of Gran Canaria.