Wolves scavenged in isolated snow-covered villages and southern Italians skied around town on Tuesday, as the Italian economy began to pay the price for the cold snap and the death toll rose to 30.

Snow kept falling in the north of Italy, with temperatures dropping to minus 25 degrees Celsius (minus 13 degrees Fahrenheit) in Marcesina on the shores of Lake Garda, and black ice in Calabria and Sardegna in the south.

A woman froze to death in Monza, near Milan, on Tuesday, as did a mentally ill man who had wandered off from the institute where he was being looked after in the Campania region.

A homeless man was found dead under a cardboard shelter in Ferrara, while a woman who had been admitted to hospital several days ago died of hypothermia.

Seven people were injured in Trieste in northern Italy when they were blown off their feet by a gale, despite chains and ropes stretched along streets in the city which is often battered by a fierce northern wind known as the Bora.

One woman died on Saturday when she was knocked to the ground by the wind.

Residents in Potenza, in the southern Basilicata region, took to their skis to get around amid a heavy snowfall which blanketed the sleepy city.

In the town of L'Aquila, devastated by an earthquake in 2009, snowed-in residents warned of food shortages and wolves scavenged in the white, deserted streets of the nearby town of Trasacco, the Corriere della Sera daily said.

Life in the centre of Rome returned to normal after days of chaos in the wake of the heaviest snowfall in 27 years, but schools remained closed and thousands in the surrounding region were still without electricity or heating.

The capital's main shopping thoroughfare, the Via del Corso in the historic centre, was closed to traffic after fears that vast ice-sheets could slide off roofs and plummet onto passing pedestrians and vehicles.

Biting temperatures and widespread snow and ice have caused up to 500 million euros ($660 million) worth of damages to Italy's agriculture sector so far, the Confagricoltura association said Tuesday.

The cold snap is forecast to continue at least until the weekend.

The economic development ministry activated a plan Monday to maximise gas supplies to vulnerable households by reducing gas supplies to industrial clients and switching from gas to oil-fired power stations.

2,000 companies -- from steel to paper factories -- have contracts which mean their gas supplies can be suspended if necessary, and 300-400 of them have been affected so far, according to the Gas Intensive consortium.

The consortium's head, Paolo Culicchi, said that should the companies be cut off for more than three days, Italy would lose 1.0 percent of its gross domestic product.

Energy policy expert and former minister Alberto Clo' told Il Mattino newspaper: "There is no need to panic, Italy will not run out of gas."

"There won't be any scenes like The Day After Tomorrow," he said, in reference to the 2004 apocalyptic film about a modern-day ice age.

"After a mild winter and with industry running at low capacity, we haven't drawn very much yet from our reserves," he said.