Within minutes of the first Nato depleted uranium air raids around the Bosnian Serb town of Doboj in 1995, Milan Simic, the municipality's civil defence commissioner, went to look at the wreckage. Some of the bombs were targeted on mountain-top Serbian military installations, others on a television transmitter and an ammunition depot in the town.

"About 10 months later, our people started reporting strange things," he said. "Animals were being born with deformities, particularly in cattle. We found calves born with large amounts of their skin missing but with enormous ears and huge paws. They did not live very long.

"Then we found the vegetables and grass, after a few months, looked brown and burnt in the area of the bombings. The trouble is that no one at the time was able to document this – there was a war on."

But Mr Simic can recollect his personal health problems with documentary clarity. "I didn't know anything about uranium or radiation. But in July last year, I suddenly found my throat had tightened. I couldn't speak. I lost 22 kilos in 18 days. If I hadn't been sent to the radiation specialists in Belgrade and been admitted to the military clinic, I would have died."

Mr Simic is right about the lack of documents. Scientific inquiry has little scope in time of war. And there are unpleasant rumours circulating in northern Bosnia that evidence connecting depleted uranium (DU) munitions with ill-health has been suppressed on the orders of Biljana Plavsic, now before the war crimes tribunal in The Hague and anxious – perhaps – to offer Nato governments something in return for modest treatment at her trial.

But detailed studies of the steady increase in cancers among Bosnian Serbs after Nato's 1995 raids, the so-called "epidemiological research" British and other governments demand before they will acknowledge that DU weapons cause cancers among civilians, may soon be available.

The semi-autonomous Serb Republic is already reporting a fivefold increase in cancers over the past five years, with Banja Luka, heavily bombed in 1995, among the worst affected. The medical authorities there say cancer cases climbed from 816 in 1999 to 1,800 in 2000.

In Doboj, which releases pre-war and post-war medical statistics on Monday, a tour of the regional hospital produces repeated assertions from doctors that the rate of tumours and respiratory infections now is two and a half times greater than before the war. Dr Branko Dabovic, the silver-haired head of the infection department, has never seen such a rise.

"There was a significant increase in malignancies and skin infections after the bombings," he said. "In the one year after, we had more herpes zosta virus cases than in the 30 years I've worked here. We treated 200 cases here and 7,800 at their homes."

Dr Dabovic chooses his words carefully. He is a medical man, not a politician. "We are aware there is a serious rise in patients suffering from immunity decrease. We have been wondering why people should suddenly suffer a decrease in immunity among all ages and both sexes. I tried to prove scientifically that it was bad food or stress. But it wasn't. We had one man come here who was under 20. He had felt fine the day before. We diagnosed acute leukaemia. Within four days, he was dead."

Dr Zora Drobac, a senior dermatologist, said: "There are a larger number of tumours among children and a greater number of malignant tumours. The skin problems are almost always face, hands and neck – which are exposed."

The urology department reports an increase in lung tumours, around 40 cases a year in 1999 and last year, just 20 a year before the war.

For those who believe these claims are merely a variation of Serbian Bosnia's wartime propaganda, all seven doctors interviewed by The Independent at Doboj hospital insisted further studies would be necessary before scientific proof could connect the frightening rise in ill-health to DU munitions.

But it is impossible not to be moved by Filip Andreato, pale and fearful, as he lies in the arms of a nurse in the paediatrics department, at eight years old, unable to comprehend why he cannot breathe fully. Or 11-month-old Ognjen Radonic, whose mother, Mirjana, was close to the Nato bomb explosions at Doboj's ammunition dump. "There were massive explosions and smoke like a small mushroom,"she said.

Ognjen was born four years after the raids, but so were many of the other children now suffering from respiratory failure and unexplained leukaemias in the former war zones of southern Iraq. At the end of one bed, a small boy in blue sits, fiddling with a set of playing cards. Dusko Duric has a serious lung infection, the first any of his family have suffered.

Are they victims of Nato? The doctors are putting their research data together for publication. In 1999, when research was published on regional cancer increases by six medical practitioners at the Doboj hospital, led by the head doctor, Obrad Filipovic, it was ignored in the West. Its evidence was too disturbing to be examined. It was compiled, said Dr Filipovic, because of "the enormous increase in the frequency of skin tumours of the face and neck at the end of the war."

Their research showed that in the pre-war 1990-1991 period, Doboj, with a population of 450,000, treated 154 tumours, of which 130 were malign (86 baso-cellular and 44 plano-cellular). In 1996 and 1997, with a post-war population of only 140,000, the hospital operated on 144 tumours, of which 101 were malignant (75 baso-cellular and 25 plano-cellular). In other words, the doctors operated on almost the same number of tumour patients in the two years after the war as they did when the population was more than three times the size. Of the patients, 98 per cent were Serbs, whose areas were, of course, the target of Nato raids with DU shells. No one knows exactly how many DU rounds were used on Doboj – Nato admits DU was used. But a Serb news crew filmed the aftermath of one raid, and their videotape contains frames of a fragment of munitions at Usara carrying the Nato coding: "Wing Assembly 96214, ASSY 872128, Serial No: 80-230893. Date: M (letter damaged)– G12."

No doubt Nato in Brussels will know if that carried a DU warhead.

* Nato said yesterday that its investigation had found no "significant" health hazard to S-for troops or to the present civilian population at the Sarajevo suburb of Hadzici from the DU ammunition rounds which have been discovered at the former military plant more than five years after it was bombed.