Twenty-six migrants have been rescued by an Italian cargo ship off the coast of Libya, but dozens more are said to be missing.
Video footage released by the Italian coastguard showed the survivors being transferred to one of its vessels, after it had responded to a satellite phone call and diverted the merchant ship to the area.
The ship found a rubber boat that had taken on water and rescued the two dozen aboard. But Italian media said at least another 70 were feared dead; other estimates put the figure at 84.
The previous day, the Italian navy rescued nearly 240 people including some 70 children from two rubber boats off the Libyan coast.
No details were given of their countries of origin.
Some 27,000 migrants have reached Italy by boat this year.
The International Organisation for Migration estimates that more than 1,200 people have died in 2016 trying to reach Europe by sea, more than half of them on the central Mediterranean route.