BUDAPEST, Hungary (AP) _ The European Union's senior environmental official has called for an international task force to investigate a cyanide spill that contaminated two major Balkan rivers.

EU Environment Commissioner Margot Wallstroem said in Budapest Thursday she wanted a commission set up ``within a few weeks'' to assess the extent of contamination from the spill and to prevent similar accidents in the future.

Wallstroem also announced that her office would begin an inventory next week of other potential European ecological time bombs.

Tons of cyanide poured into Romania's Lapus River on Jan. 30 from a containment dam at gold mine. The poison passed through Hungary and Yugoslavia via the Szamos and Tisza rivers before returning to Romania on the Danube.

Cyanide is used to separate gold ore from the surrounding rock.

Angry farmers near the spill site at a gold mine close to Baia Mare, Romania, told Wallstroem on Thursday of earlier spills that they knew nothing about until they found livestock dead or blinded.

Romania's environment minister acknowledged for the first time the magnitude of the pollution.

``We regret the unfortunate accident that neither Aurul SA nor Romania wanted,'' said Environment Minister Romica Tomescu, referring to the gold-mining company responsible for the pollution.

``Romania did not ever want to hide or play down the magnitude of the accident,'' said Tomescu, addressing reporters in Szolnok, Hungary.

``Romania did not ever want to hide or play down the magnitude of the accident,'' Tomescu said, addressing reporters in Szolnok, Hungary.

In Vienna, Austria, Philip Weller, director of the World Wildlife Fund's Danube Carpathian Program, described the spill as ``clearly one of the major river disasters that has happened in Europe in the last decade.''

He compared it to the 1987 spill of tons of agricultural chemicals into the Rhine at Basel, Switzerland, after fire damaged a chemical warehouse owned by Sandoz AG.

At the time, environmentalists said it might take a decade for the Rhine to fully recover. Wallstroem on Thursday told reporters that the impact of the cyanide spill may first ``come in 20 or 50 years.''

International officials say preliminary findings indicate that about 100 tons of cyanide escaped, along with tons of toxic heavy metals.

Hungarian Environment Minister Pal Pepo said Thursday the spill was ``the biggest accident in the history of Hungary.'' He said that rehabilitation of the rivers might take up to ten years.

His statement was challenged by Petre Marinescu, who heads the Romanian state water company. Marinescu said the fish had died not because of the cyanide concentration in the water but because of substances used afterward to neutralize the chemical.

A joint commission of experts from both countries is currently investigating the cause of the spill.

The World Health Organization earlier expressed concern that heavy metals such as lead and cadmium also might have escaped into the water, potentially posing a far greater health threat.

In Yugoslavia, ecologists warned of long-term food poisoning, not only through the cyanide but also because of dangerous concentrations of lead and other toxic metals that have already killed tons of fish in the contaminated Danube and Tisza rivers.