The Italian coast guard says some 4,000 migrants have been rescued from the Mediterranean sea in 22 separate operations in one day.

Cmdr. Cosimo Nicastro said that number may well be a record, given the previous highs ofmigrant rescues have been up to 6,000 over two days. Questions have been sent to the AFM as to whether they were involved in the rescue operations, but no replies have yet been received.

Tens of thousands of desperate migrants have been leaving the lawless coast of Libya in decrepit smuggling boats, hoping to reach the shores of Italy's southern islands. Many of the boats sink or capsize, and hundreds drown each year along the journey.

Earlier, the Italian coast guard said that a migrant boat had overturned off Libya's coast with an unknown number of passengers on board. The Associated Press  said that so far 88 people have been rescued.

Coast Guard. Cmdr. Cosimo Nicastro told AP that the capsized boat was first spotted Thursday by an aircraft participating in the European Union monitoring operation. The Italian coast guard responded with two rescue vessels to the location some 30 miles (50 kilometers) off Libya's coast.

Nicastro said 88 people had been rescued from the capsized wooden boat. He said he didn't have any information about whether any bodies were recovered or how big the boat was.

This was one of the 22 search-and-rescue operations underway Thursday.

In another instance, a Libyan navy spokesman said a total of 766 migrants have been rescued by Libyan coast guards.

Col. Ayoub Gassim told The Associated Press that the rescued migrants were found in two groups: one of 550 near the western coast city of Sabratha and the second of 216 off Zwara.

He also said that two boats were found empty in the area between the two cities, and only four bodies were retrieved while the rest of its migrants are feared dead. He didn't elaborate, saying that he doesn't have enough details about the empty boats.

Questions were sent to the AFM regarding their involvement, and in response they said: "The operations in question were entierly dealt with by the Italian Coast Guard.The AFM contributes to Frontex Op Triton, Frontex Op Poseidion and EUNAVFOR MED Sophia. AFM Air and Maritime assets and their crews, as well as personnel from all AFM Units, are provided on a regular basis to EU operations concerning irregular migration. Therefore, all EU maritime entities that contribute to such missions (including Malta and the AFM) are involved in the EU's efforts to save lives at sea".