Six people died in Italy on Tuesday after a rescue helicopter crashed in the mountains in the central province of L'Aquila, authorities said.

The helicopter fell from a height of about 600 metres at Monte Cefalone near Campo Felice ski station in the Abruzzo region, the national emergency medical service said in a statement.

The crew had just rescued an injured skier, and was bringing him to hospital in L'Aquila. There was low visibility in the area due to heavy fog at the time of the crash, which seemed to have occurred just minutes after 12 a.m. local time.

The aircraft's mission was not linked to the avalanche that buried the Rigopiano hotel in the same region on January 18, claiming at least 16 victims so far, authorities specified.

Neither was it being used for the emergency caused by a series of quakes combined with severe weather that hit central Italy -- and especially the L'Aquila province -- during last week.

All six people on board were found dead, including an E.R. doctor and a nurse, rescuers said. Three members of the Alpine Corp of the Italian army were among the victims, and two of them had taken part in the rescue mission at the hotel Rigopiano in the last few days.

The injured person assisted by the helicopter was a 50-year-old man from Rome, according to local media.

"It will take time to exactly understand how the accident occurred," Marco Cordeschi, an engineer and security consultant for L'Aquila city council, told Ansa news agency.

"Yet, we can assume the crash happened because of the fog, since that was a known flight route."

The Italian national authority for flight security (ANSV) said it has launched a probing into the incident, and sent inspectors in the area.

Severe weather conditions also hampered the rescue operation, and teams were able to locate and reach the wreckage of the helicopter only hours after the crash.

Witnesses reported to state broadcaster RAI TV they saw the helicopter flying very low, just before disappearing into the fog. Others said they heard a loud explosion.

The Campo Felice is a well-known skiing destination at about 1,500 metres in the Apennine Mountains, some 120 kilometres east of Rome.

source: Xinhua