Hundreds of people were rescued on Saturday after a ferry caught in a snow storm hit a breakwater off Italy, as a vicious cold snap that has claimed over 260 lives across Europe tightened its grip.

Ukraine has suffered the heaviest toll with 122 deaths, including many who froze to death in the streets, as temperatures plunged to as low as minus 38.1 degrees Celsius (minus 36.5 Fahrenheit).

Airports were shut, flights and trains delayed, and highways gridlocked as emergency services raced to clear falling snow.

In Italy, the ferry Sharden hit a breakwater shortly after setting off from the port of Civitavecchia near Rome, causing panic among the 262 passengers who feared a repeat of a cruise ship tragedy in the area last month that killed 32.

Coastguard spokesman Carnine Albano said the accident, which tore a 25-metre (80-foot) hole in the ship's side above the waterline, happened after the vessel was buffeted by a violent snow storm from the north-east.

All passengers were evacuated and no injuries reported.

The heaviest snowfall in 27 years in Rome caused the capital better known for its warm sunshine to grind to a halt, with taxis and buses unable to navigate through the icy streets without snow chains.

Parts of the Venice lagoon also froze over.

A 46-year-old woman died in Avellino, near Naples in southern Italy, after a greenhouse roof laden with snow collapsed on her and the ambulance failed to get through the blocked roads to her in time.

A homeless man in his sixties of German origin was found dead, apparently of cold, in the central town of Castiglione del Lago.

But as Europe huddled indoors for warmth, Russian gas giant Gazprom said it could not satisfy western Europe's demand for more energy.

"Gazprom at the moment cannot satisfy the additional volumes that our Western European partners are requesting," the company's deputy chairman Alexander Kruglov said at a meeting with Prime Minister Vladimir Putin, according to Russian news agencies.

Frigid temperatures even edged into north Africa, with the temperature forecast to drop to minus 5C (minus 20F) in Algiers on Saturday night.

In Algeria's eastern region, a 17-year-old man was assumed killed after he was swept away by a swollen river. Many domestic and international flights were cancelled.

In Poland, the death toll rose to 45 as temperatures reached minus 27C (minus 32F) in the north-east. In Romania, four more victims were found, bringing the number of fatalities in the country to 28.

The cold snap has also killed people in Latvia, Lithuania, Estonia, Bulgaria, the Czech Republic, Italy, Slovakia, France, Austria and Greece.

Snow fell in Bosnia for the second straight day, paralysing traffic, with one patient dying as the ambulance was unable to reach his village in the south of the country.

Two people were found dead in Croatia on Saturday, in the southern region near the Adriatic coast and the main port Split where the snow has surprised inhabitants, Hina news agency reported.

In Serbia, a man was found dead in the southern town Lebane as the authorities in 28 municipalities, mostly in remote mountainous regions in the south and southwest, declared a state of emergency.

Maric said some "60,000 people have been, or 25,000 households, have been cut off by snow" with emergency services engaged in clearing off the areas and bringing the necessities to the population.

In Bosnia, one man was found dead in southwestern town Mostar and the authorities and public transportation was disrupted in the capital Sarajevo, which saw its airport closed.

Even Croatian and Serbian Presidents Ivo Josipovic and Boris Tadic were forced to postpone their departure from a regional meeting, as they were blocked in the ski resort of Jahorina, near the Bosnian capital.

In tiny Montenegro, where one person was found frozen to death in a village, many hamlets in the mountainous north were cut off. Rescuers managed to evacuate 120 people, among them 31 school children from neighbouring Albania on a field trip, Interior Minister Ivan Brajovic said.

Both airports - in the capital Podgorica and the Adriatic port of Tivat - were also closed to traffic, while the authorities ordered a railway service to be halted fearing mountainous avalanches.

The Netherlands' Amsterdam-Schiphol airport meanwhile reported "dozens of delays and cancellations," and London's Heathrow, the world's busiest in terms of international passenger traffic, cancelled 30 per cent of Sunday's flights as it braced for heavy snow and freezing fog.

In France, snow fell from Lille in the north to Marseille in the south, though the west of the country and the capital Paris were spared.

Five hikers who were lost in the Jura mountains between France and Switzerland were rescued on Friday, with two suffering from severe hypothermia. Temperatures in the region were as low as minus 15C (minus 26F).