Concern is growing in Europe over the so-called Balkan War syndrome as the death toll rises among soldiers who served during the conflict.

On Thursday, the Netherlands became the latest country to begin an investigation after two soldiers – one formerly based in Kosovo and the other in Bosnia – died of leukemia.

At least 12 soldiers, including four French and six Italian servicemen, have died of leukemia which some say may be related to NATO's use of ammunition containing depleted uranium. Spain, Portugal, Turkey and Finland are all screening their Balkans veterans.

On Wednesday, Italy asked NATO to formally investigate the growing concerns.

"The issue has taken a serious turn and the alarm caused is more than legitimate," Italian Premier Giuliano Amato said in a newspaper interview.

NATO's force in Bosnia, SFOR, acknowledged using depleted uranium ammunition there in late 1994 and 1995, but denied that it was making soldiers sick.

In Kosovo, U.S. planes used the ammunition mostly in the central, western and southwestern parts of the province – areas where Italian, Spanish, and Portuguese peacekeepers later were deployed.

U.S. veterans' groups say depleted uranium is partially responsible for so-called Gulf War syndrome, something the Pentagon has called "unlikely." Documents show that U.S. forces fired about 944,000 rounds in Iraq and Kuwait.

NATO will have top-level discussions on the issue on Saturday, the Italian Foreign Ministry said. NATO ambassadors are also expected to discuss it at their regular meeting on Jan. 10.

A UN team is doing a study on the syndrome following a trip to Kosovo in November. It's expected to report its findings in February.

Canada's Department of Defence said there has been no increase in incidents of cancer among vets tested so far.

In February, the government began a voluntary screening program. It's tested 90 Gulf War vets and 11 Balkans vets so far. Levels of depleted uranium were consistent with the general population.

Spain also said its preliminary results showed normal levels.