(AP) - Snezana Pavlovic's gloved hand opens a jar filled with a soil sample from just outside of Kosovo. Immediately, the Geiger counter in her other hand bleeps, throbbing faster and faster.

Pavlovic is among the top Yugoslav scientists convinced that the dirt offers proof that NATO contaminated Kosovo with toxic levels of depleted uranium during its bombing campaign in 1999 - no matter what the Pentagon may say.

"Just because people can't see it and it's difficult to detect doesn't mean the depleted uranium is not a killer," Pavlovic said.

Yugoslav authorities have charged that the NATO alliance contaminated large swaths of southwestern Kosovo during the 78-day bombing campaign. Their data was widely dismissed, however, because it was seen as part of a concerted propaganda effort by former Yugoslav President Slobodan Milosevic's regime.

Now a new, pro-democracy government is in place, and state scientists and Yugoslav army experts are eager to present their data once more. Hoping to show legitimate science backs their claims, they opened the country's sole nuclear laboratory for a rare tour Friday.

NATO admits it targeted Yugoslav army positions in the bombing campaign last year using ammunition containing depleted uranium, an extremely dense metal used against armoured vehicles because of its high penetrating power. But the United States, which used the ammunition in the Gulf War as well, has denied any link between illnesses and exposure to depleted uranium.

Depleted uranium, the spent fuel of nuclear reactors, is 40 per cent less radioactive than uranium in its natural state.

Its use came under renewed scrutiny in recent days, after Italy noted about 30 cases of serious illness involving soldiers who served in missions in Kosovo or Bosnia. Twelve of them developed cancer, and five have died. Four French soldiers who served in the Balkans are being treated for leukemia.

A number of European countries have begun screening Balkan veterans.

Scientists at the Vinca nuclear laboratory, eight kilometres from Belgrade, say the examination is long overdue. Since the first days of NATO's 1999 bombing, Pavlovic's team has been busy testing samples at the institute, a sealed-off and guarded compound of a dozen buildings spread over a hectare.

Many medical experts are skeptical that the depleted uranium caused cancer and other illnesses reported by veterans. They say depleted uranium vaporizes instantly and a person would have to be very close to an explosion and be there within seconds to be affected. But others argue that not all the depleted uranium vaporizes immediately and radioactive derivatives can linger in the air for months.

The head of a UN environmental task force said Friday that remnants of ordnance containing depleted uranium are littering the ground in Kosovo.

"It was surprising to find remnants of DU (depleted uranium) ammunition just lying on the ground," nearly 1½ years after NATO's bombing campaign, said Pekka Haavisto, head of the UN Environment Program's depleted uranium assessment team.

In November, the team of UN scientists toured 11 sites in Kosovo targeted by ammunition containing depleted uranium. They collected hundreds of water, soil and vegetation samples.

At eight of those sites, team members found slightly higher levels of radiation, or pieces of ammunition, Haavisto said. Five of the sites visited were in the Italian-patrolled sector of the province, while six were in the German-patrolled sector.

The uranium now is concentrated along a belt of land stretching from just outside of Kosovo's southwestern city of Prizren, along a route connecting the towns of Djakovica and Decani to the north.

The metal will filter into ground water and ultimately move into the food chain, said Col. Milan Zaric, a Yugoslav military expert on radioactivity.

Zaric points out that while withdrawing from Kosovo, Yugoslav troops left behind tanks and armoured vehicles destroyed by NATO ammunition containing depleted uranium. Ethnic Albanian children posed for cameras amid leftover ordnance.

"Because NATO used this ammunition, it has a moral duty to clean up the sites in the peace mission that followed the war, however costly such a procedure is," Pavlovic says.