RESCUE workers on skis have reached a four-star spa hotel buried by an avalanche in earthquake-stricken central Italy.

They reported no signs of life as they searched for around 30 people believed trapped inside.

Three bodies were recovered as heavy vehicles struggled to get to the scene.

Two people escaped the devastation at the Hotel Rigopiano, in the mountains of the Gran Sasso range, and called for help - but it took hours for responders to arrive to the remote zone.

Days of heavy snowfall had knocked out electricity and phone lines in many central Italian towns and hamlets, compounded by four powerful earthquakes that struck the region on Wednesday.

It was not immediately clear which, if any, of the quakes triggered the avalanche. But firefighters said the sheer violence of the snow slide uprooted trees in its wake and wiped out parts of the hotel, leaving only some structures standing and others down the mountainside.

"There are mattresses that are hundreds of metres away from where the building was," Luca Cari, firefighters' spokesman, told the ANSA news agency.

The hotel in the Abruzzo region is about 30 miles from the coastal city of Pescara, at an altitude of about 1,200 metres.

The area, which has been buried under snowfall for days, is located in the broad swathe of central Italy between Rieti and Teramo that was jolted by Wednesday's quakes, one of which had a 5.7 magnitude.

Accounts emerged of hotel guests messaging rescuers and friends for help on Wednesday, with at least one attempt at raising the alarm rebuffed for several hours.

Giampiero Parete, a chef on holiday at the hotel, called his boss when the avalanche struck and begged for him to mobilise rescue crews.

His wife Adriana and two children, Ludovica and Gianfilippo, were trapped inside, employer Quintino Marcella said.

Mr Parete had left the hotel briefly to get some medicine for his wife from their car, and survived as a result.

"He said the hotel was submerged and to call rescue crews," Mr Marcella said, adding that he phoned police and the Pescara prefect's office, but that no one believed him.

"The prefect's office said it wasn't true, because everything was OK at the hotel."

Marcella said he insisted, and called other emergency numbers until someone finally took him seriously and mobilised a rescue, starting at 8pm, more than two hours later.

When rescuers on skis arrived at the hotel in Florindola in the early morning hours of Thursday, they found just two people alive: Parete and Fabio Salzetta, identified by Italian media as a maintenance worker at the hotel.

There were no other signs of life, with rescue crews saying they yelled out but heard no replies, and were using rescue dogs.

Parete was being treated for hypothermia at a hospital in Pescara. The Romanian foreign ministry reported three Romanian citizens missing in the hotel - an adult and two children; they were believed to be Parete's family.

Aerial video shot by helicopter crews showed rescue workers on top of the snow-covered hotel, digging holes down to try to get in.

Civil protection authorities said that around 30 people were missing. By Thursday afternoon, three bodies had been removed.

Civil protection officials said the risk of further avalanches was factoring into the search effort.

Premier Paolo Gentiloni, arriving at the civil protection headquarters in the area at midday, sought to deflect criticism of the rescue efforts and urged authorities to redouble efforts to reach people isolated by the quakes and snow, which had dumped as much as three metres in some places.

Residents have been complaining for days that they have been without electricity and phone service and have been house-bound because of what Gentiloni called a "record snowfall".

"I ask everyone if possible to multiply their efforts," Gentiloni said.

"I ask politicians to show sobriety respecting the difficulty of the situation and the commitment of civil and military crews who are responding."