Storms and floods in western Ukraine and neighbouring Romania have killed 26 people, forced the evacuation of tens of thousands and damaged scores of bridges, officials said Monday.

Romanian President Traian Basescu warned the region faced an "ecological disaster" if lakes containing potentially lethal mining waste were allowed to overspill in the north of his country.

Fifteen people were killed in the Ivano-Frankivsk region in southwest Ukraine while seven people were killed in Chernivtsy, the emergency situations ministry said in a statement.

Rescuers evacuated more than 19,800 people from their homes because of the severe storms and floods that also hit northeastern Romania, the ministry said.

More than 40,000 houses and 34,000 hectares of farmland remained partially flooded on Monday in Ukraine, while more than 900 bridges and hundreds of kilometres (miles) of roads were damaged.

One hundred villages were without electricity, the ministry said.

In Romania, the death toll following five days of flooding in the north rose to four on Monday with the discovery of the body of a teenager carried away by the floodwaters. Another person remains missing in northeastern Suceava.

Authorities had reported on Sunday that a 30-year-old mother, her son and another youngster died in Maramures county when a landslide swept away the house in which they had taken refuge, up on a hill.

A total of 11,720 Romanians had been evacuated from their homes in the north, the authorities said.

Basescu warned that a totally different kind of disaster could still be to come as waste lakes in the north of the country threatened to burst their banks.

"A breach has formed in the Lake Colbu 2's protection dyke and the water containing the residue of heavy metals and probably of cyanide, has poured into Lake Colbu 1, posing a threat for the entire region," he said.

"We must act quickly to make sure that this second dam doesn't give way as well, if not we risk being confronted by an ecological disaster."

According to local official Mircea Man, more than eight million tonnes of mining waste are stocked in the two containment lakes.

"If these residues were to pass into rivers in the region, they would cause very serious pollution not only to our waters but also to cross-border (rivers) like the Tisza."

Overspill from a waste lake in northern Romania in January 2000 was the origin of serious cyanide pollution in several rivers, including the Danube, which led to a sharp rise in fish deaths, notably in Hungary.

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