In the first operation, a Maltese vessel rescued more than 200 migrants on two rubber dinghies who had put out an SOS call while they were still in Libyan waters.
A boat flying a Bahamas flag also rescued 118 migrants, while in another operation a Navy vessel called on a tugboat to rescue 175 migrants from two more boats.
Meanwhile this morning, Italian divers found another body from the refugee shipwreck last week off the coast of the island of Lampedusa, raising the death toll in the tragedy to 312.