A flotilla of ships saved 668 migrants on Saturday from smugglers' boats in distress in the Mediterranean Sea off the coast of Libya, Italian authorities said - bringing the week's total of migrants plucked from the sea to a staggering more than 13,000 people.

The rescues by the Italian coast guard and navy ships, aided by Irish and German vessels and humanitarian groups, are the latest by a multinational patrol south of the Italian island of Sicily.

The Irish military said the vessel Le Roisin saved 123 migrants from a 12-meter-long rubber dinghy and recovered a male body. A German ship patrolling to intercept smugglers' boats also was involved in four separate rescue operations, the Italian coast guard said on Saturday evening.