Italy called for a NATO investigation Friday into whether one of the alliance's warships ignored a migrant boat's distress call amid unconfirmed reports that dozens died during the journey from Libya.
On Thursday, Italy's coast guard rescued hundreds of people packed aboard a boat stranded between Libya and the southern Italian island of Lampedusa, which is near Africa's coast.
The relief organization Medecins Sans Frontieres said migrants arriving at Lampedusa's dock told the group's staff that they had witnessed "dozens of people die" because of the harsh conditions.
Describing the survivors, Dr. Marco Testa said: "Most of these people were dehydrated or suffering from hypothermia," according to a statement from the organization _ also called Doctors Without Borders.
Italian media, without citing sources, said some migrants told their Italian rescuers that the bodies of those who died were tossed overboard by survivors. Coast guard officials have said that there has been no independent confirmation, and searches had failed to find any bodies in the sea.
The Italian reports, again without citing sources, said the boat had sent an SOS to a nearby NATO warship, but received neither help nor a response while being stranded for six days.
Foreign Minister Franco Frattini requested that NATO conduct a formal investigation and said he also instructed Italy's NATO ambassador to ask the alliance to consider the care of civilians fleeing Libya on rickety boats as part of the U.N. resolution that allows military action to protect civilians in Libya itself.
NATO launched its bombing campaign to protect civilians from attacks by the regime of Moammar Gadhafi on the basis of that resolution. About 24,000 migrants have reached Italy by sea since the bombing campaign began in March.
NATO acknowledged in a statement Friday afternoon from its command in Naples that Italian authorities had informed the alliance's maritime command about "a distress call of a ship." It said NATO then confirmed with the Italian authorities that Italy was responding with three ships and helicopter support.
"Facts of the incident are still emerging and we are working closely with Italian authorities to fully clarify the matter," the statement said. "NATO has a long-standing commitment to render assistance in emergency situations at sea."
NATO cited recent examples of that assistance, including an incident on July 10, when a NATO ship helped a vessel in distress about 75 miles (120 kilometers) off the Libya coast, providing "medical support, food and mechanical assistance to the distressed migrants." It added that the migrants were taken aboard the NATO ship because of a "deterioration of the humanitarian situation on board."
In a separate case, police in Sicily have detained six alleged human traffickers as suspects in the deaths of 25 African migrants aboard another overcrowded boat trying to reach Italy from Libya. The men taken into custody Friday were identified as citizens of Somalia, Morocco and Syria.
Authorities said they were operating the boat that was boarded Monday by the coast guard off the Italian island of Lampedusa, which has been the destination of scores of rickety and overcrowded boats carrying would-be immigrants.
The coast guard said the 50-foot (15-meter) boat carried 296 people, many packed in the hold.
Alessandra Rizzo and Frances D'Emilio in Rome contributed to this report.