BRUSSELS, Jan 4 (AFP) - The European Union joined a growing number of European governments Thursday in expressing alarm at a possible link between depleted uranium munitions used in the Balkans war and a rash of cancer cases among NATO troops who served in the conflict.

As France revealed that four of its troops who had served in the region had leukemia, EU Commission President Romano Prodi demanded the abolition of the tank-busting weapons if there was risk of radioactive contamination.

An EU spokesman said Thursday that the union was considering launching its own investigation into the use of the controversial hardware in the Balkans, which is due to be discussed at a NATO meeting next week. "It is obvious that if there is even the smallest risk, these arms must be abolished," Prodi said on Italian radio.

Six Italian soldiers have died of leukaemia while five fatal cases of cancer had been detected among Belgian soldiers and several leukaemia cases reported among Dutch Balkans veterans.

Belgium, France, Italy and Portugal have all called on NATO this week to provide additional information on the depleted uranium projectiles and their potential health impact.

Depleted uranium is a highly dense metal used in the ammunition of weapons used to penetrate the armour of tanks or bunkers. NATO insists there is no evidence to suggest the shells pose a health hazard to friendly troops.

But critics believe fragments or dust released when the shells impact are highly toxic and can come into contact with soldiers on the ground. The scare over weapons is likely to revive questions about illnesses besetting veterans of the 1991 Gulf War, during which depleted uranium munitions were widely used.

In his statement, Prodi also said he would "immediately contact the governments of Bosnia and Serbia to talk about pollution and problems linked to the use of depleted uranium."

Prodi said he wanted the truth "not only about our soldiers but also about those who lived near them, about the civilians."

The Italian defence ministry acknowledged on Thursday that no link had so far been found between depleted uranium munitions and the deaths of the six Italians, but said it had nevertheless urged NATO to stop using the projectiles.

"I think NATO should discuss our proposal for a moratorium on these uranium-based munitions," Marco Minniti, undersecretary of state for defence, told the daily La Stampa.

French Defence Minister Alain Richard added his voice to the concern, saying: "We are calling on our American partners to be open on the subject."

The alliance insists the projectiles have negligible radioactivity and in any case are transformed by impact into a scorching vapour. Any resulting debris posing any significant risk dissipates soon after the impact.

In addition to the Balkans, the ordnance was used in Iraq in 1991 and has been linked by some to the so-called Gulf War syndrome suffered by soldiers who fought in that conflict.

Some Gulf War veterans claim 100,000 US as well as thousands of British, Canadian and French troops who took part in the 1991 conflict against Iraq suffer symptoms including memory loss, chronic fatigue, dizziness, swollen joints and lack of concentration.

None of the Turkish peacekeepers in Kosovo have been affected by radiation from depleted uranium munitions used by NATO, the Turkish general staff said Thursday, adding that several zones in southern Kosovo had been closed off due to contamination from the arms. But several cases of leukemia have been found in Dutch Balkans veterans, and Spain has launched an intensive medical examination of some 32,000 military personnel who were on duty there.