The Italian coast guard says some 4,000 migrants have been rescued from smugglers' boats off Libya in one day alone.

The coast guard said it coordinated 40 separate Mediterranean rescue operations on Thursday. One operation involved a motorized rubber dinghy, where, authorities say, a woman's body was found. More details weren't immediately available.

The high numbers are being attributed to a break in several days of bad weather and rough seas which had kept smugglers, largely based in Libya, from launching boats with migrants and asylum seekers, fleeing conflict and poverty for Europe's southern shores.

The coast guard says it has no immediate information about a report from some in the Eritrean community that a barge with some 400 migrants left Alexandria, Egypt, on Sunday and that its whereabouts are currently unknown.