Canada's

Flood waters in the Elbow River threaten a home on the west side of the town of Bragg Creek, Alberta, near Calgary. Photograph: QMI Agency/Rex Features

Power cuts in the Canadian oil capital of Calgary could last for weeks or even months, city authorities said on Sunday, after record-breaking floods swept across southern Alberta, killing three people and forcing more than 100,000 to flee their homes.

Some Calgary residents were able to return to sodden homes as rivers dropped and some evacuation orders were lifted. But Bruce Burrell, director of the Calgary Emergency Management Agency, said power restoration in the city centre, where many of Canada's oil companies have their headquarters, could take days, weeks or even months. Many oil companies were making plans for employees to work from home.

"This is an evolving situation and because of the volatility of electricity and water and the infrastructure that was damaged we have got a lot of issues with restoring power to different parts of the city of Calgary," Alderman John Mar told CBC radio. "We are facing an absolutely gargantuan task."

Heavy rains were blamed for the spilling of 750 barrels of synthetic oil from a pipeline about 70km (43 miles) south of Fort McMurray in northern Alberta early on Saturday.

"We are still investigating the cause, however, we believe that unusually heavy rains in the area may have resulted in ground movement on the right-of way that may have impacted the pipeline," Enbridge, Canada's largest pipeline company, said in an emailed statement. It has shut two major oil pipelines serving Canada's oil sands region as a precaution. Provincial authorities said it was too early to count the cost of the flood damage because rivers have not peaked in some places.

The South Saskatchewan River is expected to burst its banks in the city of Medicine Hat in south-east Alberta on Monday. About 10,000 have been evacuated. The floods already look worse than those of 2005, which caused C$400m (£248m) damage in the province.

The floods followed 36 hours of unusually heavy rainfall that pushed the volume of water in rivers to record levels. Some communities received six months of their normal rainfall within two days. Evacuations started on Thursday and the Enmax utility switched off power to central Calgary on Friday afternoon to avoid water damage to its facilities. Troops were used on Sunday morning to shore up the east bank of the Bow River in Calgary and ensure the stability of an Enmax substation.

It was unclear how much crude trading would take place on Monday after little if any trade on Friday.

Shorcan Energy Brokers, which provides live prices for many Canadian crude grades, operated out of Toronto on Friday rather than from Calgary, although there were no trades in Western Canada Select heavy blend or light synthetic crude.

Net Energy Inc, the other main Calgary crude broker, was closed on Friday and no trading took place.

As the Bow and Elbow rivers in Calgary, which during the weekend hit five times their normal flow rate, slowly receded, the scale of the damage became apparent. Roads and pavements were left covered with a layer of thick silt, fallen trees lined the riverbanks and residents pumped dirty brown water out of basements.

Police said three bodies had been found near High River, about 60km south of Calgary.

Flood water covered the grounds of the Calgary Stampede, an annual extravaganza of cows, cowboys and horses scheduled to start on 5 July. City authorities insisted the show would go ahead despite the disruption

Thousands flee flood-hit parts of Germany and Hungary

Some 23,000 people were forced to leave their homes in the east German city of Magdeburg after a dam burst on the flood-swollen River Elbe.

Although water levels in Magdeburg were reported to be receding on Monday, the city and areas of the country further north remain on high alert.

In Hungary, 1,200 people had to leave their homes but flood defences in the capital Budapest appeared to have held.

At least 19 people have died in the floods in Central Europe.

Ten victims from the Czech Republic and five from Austria died after rivers rose to dangerous levels in both countries last week.

Analysts say the damage will cost billions of euros to clean up.

Meanwhile, parts of Poland's capital Warsaw were flooded on Sunday after hours of heavy rain.

One of the city's busiest motorways was inundated, and firefighters had to help stranded drivers to safety.

Sandbags

Flood defences in Budapest appeared to have held on Monday as waters from the Danube River started to recede, having reached an historic peak of 8.91m (29 ft) on Sunday.

"We have no reports of any catastrophic situation, the situation is normalising," Budapest Mayor Istvan Tarlos said on Monday.

Hungary's Prime Minister Viktor Orban said the capital "should be out of danger by Wednesday", but warned that the focus of defence efforts was now in the south of the country.

Along more than 700km (470 miles) of the River Danube, thousands of people, including many volunteers and even convicts from the prisons, worked to reinforce earth and sandbag barriers.

More than 1,200 people have been evacuated from their homes, although no flood-related deaths have yet been reported in Hungary.

In Magdeburg, the capital of Saxony-Anhalt state, flood waters rose to 7.44m (24ft), nearly four times higher than normal (2m) - forcing some 10% of the population, 23,000, to leave their homes.

Around 700 soldiers worked to build a dam of sandbags around a power sub-station in the badly-hit area of Rothensee in a bid to keep the power on.

The Suddeutsche Zeitung newspaper reported that flood water levels had fallen slightly in Magdeburg itself on Monday, but the situation remains critical.

"We hope that the dykes will withstand the pressure over the coming days, but we can't be 100% sure," said a fire brigade spokesman, Andreas Hamann.

But other parts of Saxony-Anhalt and neighbouring Brandenburg state remain under threat as the flood crest moves north, testing flood defences already weakened by days of heavy rain.

A dyke at Fischbeck, west of Berlin, was breached overnight leading to the evacuation of nearby villages.

A railway bridge on the line between Berlin and Cologne, Frankfurt and Amsterdam had to be closed, leading to significant delays or cancellations for train travellers.

The authorities in Germany are investigating an anonymous letter threatening attacks on several dams.

The motive behind the threats is not known, but the threat is being taken seriously, says the BBC's Stephen Evans in Berlin.

Chancellor Angela Merkel is planning a crisis meeting with leaders of Germany's regions on how to share the bill for the disaster, the Leipziger Volkszeitung newspaper reported.

"We're dealing with a national catastrophe," Gerda Hasselfeldt, an MP with Mrs Merkel's Christian Social Union (CSU), was quoted as saying.

Pedestrian crossing signs were rendered redundant in Budapest as flood waters continued to rise