The bodies of 74 migrants have been found off the coast of northern Libya, and the death toll is expected to rise.
Volunteers from the Libyan Red Crescent recovered the bodies from the sea, while a torn rubber dinghy, without an engine, was found nearby.
It is believed the migrants had been attempting to reach Europe when their boat got into difficulties.
More bodies have been spotted in the sea near Zawiya but aid workers have not yet been able to recover them.
Elsewhere, 630 migrants were rescued in the central Mediterranean in two rescue operations coordinated by the Operational Centre of the Coast Guard.
In Rome, Pope Francis called for a radical change of attitude towards immigrants during a conference on migration.
He said they should be welcomed with dignity, while denouncing the “populist rhetoric“ he said was fuelling fear and selfishness in rich countries.