Serbian declared a nationwide flood emergency on Thursday and asked the EU and Russia for help. Entire towns were cut off. The slow-moving cyclone is forecast to persist until the weekend.

Serbian Prime Minister Aleksandar Vucic said his country was facing its "biggest water catastrophe in Serbia's history."

Meteorologists forecast that more than double Serbia's average rainfall for the whole of May was expected to fall within just two-and-a-half days until Friday noon.

Across Serbia, 100,000 households were without electricity. Dozens of cars and buses were stranded along flooded roads.

Schools in the Serbian capital were closed for Thursday and Friday. Major traffic routes, such as the E-75 Belgrade-Skopje highway, were submerged. Serbia's rail link to Montenegro was severed.

Waters are rising everywhere," said Serbian emergency official Predrag Maric. "We have engaged all our manpower."

At least three people were killed in Serbia, including a resident near Belgrade whom firefighters said had drowned after she refused to be evacuated.

Serbian media said at least two more people had been reported missing.

High-profile societ and basketball sporting events were postponed.

Storm also grips Bosnia, Croatia

In Bosnia, to the west, bridges were swept away by swollen rivers. The central Bosnian town of Topcic Polje, near Zenica, was bisected by landslides and raging waters (pictured).

Some residents of Maglaj, 100 kilometers (60 miles) north of Bosnia's capital, sat on roofs.

Its mayor Mehmed Mustabasic said the town was "cut off from the rest of the world."

"We have no electricity; the phones are not working," he said.

The Sarajevo government ordered the deployment of army helicopters for evacuations. EU troops in Bosnia joined rescue efforts.

Croatia also affected

High winds reaching 150 kilometers per hour forced the closure of sections of Croatia's Adriatic coastal highway.

Thousands of Croatian households have also been without power since Wednesday.

Croatia's meteorological service issued a "red alert," saying winds were powerful enough to carry debris at deadly speed.

Slovenia was also on alert because of predicted high winds.

The storm, a slow-moving cyclone, bringing sharp drops in temperature, is expected to drift to the east over the Balkans and then south to the eastern Mediterranean by the weekend.

ipj/dr (AP, dpa)