The Italian coast guard says at least 20 migrants have died after their vessel capsized off Libya's coast.
The coast guard said the ship was carrying about 500 people. At a certain point, either a wave hit or the migrants shifted to one side and about 200 of them ended up in the water.
Officials intervened and rescued most, but at least 20 bodies were seen.
The coast guard, which is coordinating migrant rescues, has dispatched other rescue vessels to the area to try to find any survivors.
The incident was one of 15 rescue operations over the past day that have saved some 1,700 people.