NATO peacekeeping troops spotted the wreckage of a U.N. World Food Program flight carrying 24 people that crashed today in rugged terrain in northern Kosovo, a NATO spokesman said.

A rescue operation was underway, though it was unclear whether there were survivors. The wreckage of the propeller-driven ATR-42 was found eight miles north of the city of Kosovska Mitrovica, NATO spokesman Sgt. Major Mark Cox said.

The plane was on its way from Rome to Kosovo's capital, Pristina, with 21 passengers and three crew members. Most were workers for private aid groups.

The six-day-a-week shuttle flight left Rome at 9 a.m. and disappeared during its approach to the Pristina airport about two hours later, NATO officials said. News of the crash was announced in Rome by Catherine Bertini, executive director of the World Food Program.

There was no official word on casualties, but a senior diplomat in Pristina, speaking on condition of anonymity, said that all on board were killed. He said the aircraft went down in heavy fog.

Officials representing NATO and the United Nations said at a news conference late tonight that they were searching a 65-square-mile area strewn with land mines remaining from the Kosovo war earlier this year. The mines prevented NATO from carrying out intensive foot patrols after dark.

No passenger list was available, but Italy's ANSA news agency said there were nine Italians aboard--the two pilots, a flight attendant, two doctors, a spokeswoman for the food program, a volunteer chemist, a policeman and an aid worker. Four of the nine were women, said ANSA.

In Ottawa, the foreign affairs ministry said one Canadian was on the aircraft.