The United States on Saturday evacuated about 400 former Libyan prisoners of war from Chad in what it called an international humanitarian effort. Libya called the move "piracy."

Ambassador Richard Bogosian refused to comment on allegations the POWs had been trained by the United States for commando operations to destabilize the regime of Libya's Col. Moammar Gadhafi.The evacuation, the second in two days, incurred the wrath of Libya, which called it an "international act of piracy" and demanded an emergency meeting of the U.N. Security Council.

Bogosian confirmed that about 200 former POWs had been evacuated on Friday in addition to the 400 who were airlifted out on Saturday.

Chad's interim president, Idriss Deby, said the decision to evacuate Libyans wanting to leave was made "in all sovereignty."

Deby toppled pro-Western President Hissene Habre a week ago after his guerrillas, armed in part by Libya, overcame the government forces in a three-week offensive.

The French news agency, Agence France-Presse, whose correspondent witnessed Friday's evacuation, quoted an American military source as saying the Libyans were being flown to Nigeria, then a third country.

The ambassador refused to specify the Libyans' destination, saying details were not finalized.

He said he did not believe there would be further evacuations.

"When the new government came in last week . . . they in effect allowed these people to leave if they wished," Bogosian said in a telephone interview.