Bitterly cold weather that has claimed hundreds of lives in eastern Europe swept westward over the continent on Saturday, blanketing Rome's Colosseum with snow for the first time in three decades and disrupting air and rail traffic.

Russian gas exporter Gazprom said it was unable to meet increased European demand as it battles its own deep freeze, and had cut its supply for a few days before returning it to normal levels.

In Belgrade, Serbia, soldiers were deployed to clear the central boulevard. Hundreds of unemployed people responded to an offer of 1,600 dinars (10 euros) pay to join snow-clearing efforts.

I haven't worked for months, and I have a family to feed, said Zoran Djidovac, a 30-year-old former metal worker. The authorities said we'll be working for several days so this money will make a change for a while.

Outside Moscow, a couple and seven of their children died in a blaze at their makeshift home overnight, apparently victims of a badly rigged-up stove that burned out of control. A 9-year-old girl was the sole survivor, Russian state TV said.

But in the Russian capital tens of thousands demonstrated to demand fair elections in a march against Vladimir Putin's 12-year rule despite -17 degree Celsius (1 degree Fahrenheit) conditions, and supporters of the prime minister staged a similar-size rally.

To the west, hundreds of passengers spent the night at Amsterdam's Schiphol airport -- one of the busiest in Europe -- as their flights were either canceled or delayed.

London's Heathrow Airport warned it would operate a much reduced service on Sunday with snow and freezing temperatures predicted to hit much of England over the weekend.

In Rome, snow blanketed ancient monuments for the first time in 27 years.

Power supplies were interrupted. About 160,000 people in central and southern Italy were without electricity. Power company Enel said 1,000 workers were trying to fix damaged power lines.

The presidents of Croatia and Serbia, who had attended a meeting with the Bosnian leadership on Friday, were holed up in the Jahorina mountains after being cut off by heavy snowfalls.

The cold spell touched North Africa, too. Palm trees bowed under the weight of snow in Algiers after a freak snowfall of at least four inches -- the first there in eight years.

The ex-Soviet republic of Ukraine, where night temperatures have been as low as -33 degrees Celsius (-27 degrees Fahrenheit) in the past eight days, registered the highest death toll as bodies continued to be found, some buried in snow in outlying parts of the country.

Stations Become Sanctuaries

Metro stations in the capital, Kiev, have become sanctuaries of warmth for the homeless. Emergency authorities have set up hundreds of heated tents around the country to provide food, drink, and shelter.

I live in a social-care home most of the time. But they throw you out of there at 8 in the morning, said Olexander, a homeless man, at a refuge in a Kiev park on Saturday. It is good they have thought of putting these up, he said, nodding at the tent. If we can just get through this frost, things will get easier.

The Emergencies Ministry said of the 122 people who have died over the past eight days from hypothermia and frostbite, 78 were found dead on the streets.

In neighboring Poland, the story was similar with the dead mainly among the homeless. Several had been overcome by fumes from primitive stoves in poorly ventilated premises. Others died by drinking too much and falling down, unnoticed, in the snow.

(Additional reporting by Sergei Karazy in Kiev, Rob Strybel in Warsaw, Vladimir Soldatkin in Moscow, Abdelaziz Boumzar in Algiers, John Irish in Paris, Aleksandar Vasovic in Belgrade, Petar Komnenic in Podgorica, Daria Sito-Sucic in Sarajevo, Martin Santa in Bratislava, Radu Marinas in Bucharest, Brian Rohan in Berlin and Steve Scherer in Rome; Writing by Richard Balmforth; Editing by Ben Harding)