There were no reports of confirmed or suspected casualties after the operations to pick up migrants packed on to 25 rubber dinghies and one wooden boat, all of which were rescued less than 35 miles from the Libyan coast.

Coastguard and navy boats took part in the rescues, along with vessels operated by Eunavformed, the EU borders agency Frontex and the charities Doctors without Borders (MSF) and Sea Watch.

The migrants were all being transferred to southern Italian ports. The latest rescues pushes to more than 66,000 the number of mostly African migrants to arrive in Italy since the start of 2016, according to figures compiled by the UN refugee agency.

The rate of arrivals is broadly in line with the pattern of last year, with officials attributing this week's high figure to calm sea conditions, which make it less risky sending overcrowded boats out to sea from Libyan ports.

More than 10,000 migrants have died trying to reach Europe via the Mediterranean since 2014, just over a quarter of the casualties having happened this year.