Hungary closed the Danube to river traffic yesterday due to thick ice, bringing shipping to a near standstill on Europe’s busiest waterway, as the continent’s cold snap death toll passed 540.

“Shipping was ordered stopped overnight Thursday to Friday because of conditions created by icing along the Hungarian part of the river,” Istvan Lang, who heads the national technical supervisory body OMIT said.

“All ships still underway must immediately head for the closest harbour,” Mr Lang, quoted by MTI news agency, said.

Hungary’s navy had to send its biggest icebreaker, the Szechenyi, to try to break open the frozen river at Budapest.

“I’ve not seen so much ice on the Danube since 1985,” said its captain, Dezso Kovacs.

The freeze had already forced other countries along the Danube, including Austria, Croatia, Serbia, and Bulgaria, to suspend river traffic.

The 2,860-kilometre river, which flows through 10 countries and is vital for transport, power, irrigation, industry and fishing, was nearly wholly blocked, from Austria to its mouth on the Black Sea.

Forecasters expect the cold snap, which started two weeks ago, to continue until mid-February.

In Romania, the death toll had risen to 57 since the start of the cold spell, with more than 20,000 people still cut off by snow in the east of the country, with food supplies running out, officials said.In the southern village of Varasti, inhabitants had to tunnel their way out from under four metres of snow, sometimes exiting through their top windows.

There were fresh snowfalls in Italy, where the deep freeze has killed more than 45 in the past 10 days.

A 42-year Romanian woman, believed to be sleeping rough was found frozen to death in a cave in the Rome suburbs, while a man was reportedly attacked by scavenging stray dogs near Rimini. On the island of Sardegna, a man died apparently from hypothermia shortly after coming out of a hospital dressed only in pyjamas and slippers.

Motorways banned some heavy truck traffic in the northeast of the country, while rail services and Bologna airport experienced delays. In Rome, where forecasters predict up to 30 centimetres of fresh snow, all schools were closed yesterday.

In Bulgaria where 32 have died, authorities continued a massive relief effort in the southeastern village of Biser, submerged under the icy waters of a nearby dam that burst on Monday. The ensuing floods killed 10 people.

In France, the death toll increased to at least 12: Paris officials said two homeless men, a Pole and a Romanian, had died of cold over the past week.

And a nuclear reactor at the Cattenom plant shut down because of a fault, placing fresh pressure on the already strained national power grid yesterday, state energy giant EDF said.

So far the deep freeze has claimed 37 lives in the Balkans – 16 in Serbia, 11 in Bosnia and Herzegovina, five in Slovakia, four in Montenegro, three people in Croatia, two in Macedonia and one in Albania.