The scene (Photo: Alessandro Della Valle/EPA)

Dozens of people are likely to have been killed in an explosion at a bar in a Swiss ski resort. This was reported by the agency Reuters with reference to the police.

On Thursday, dozens of people were killed and about 100 injured in an explosion that hit a crowded bar during a New Year's Eve party in the Crans-Montana ski resort, law enforcement officials said.

The Italian Ministry of Foreign Affairs reported that, according to Swiss police, about 40 people were killed, but the police did not specify details at a briefing on the incident, limiting themselves to the number of "dozens."

The incident occurred around 01:30 local time (00:30 GMT) in a bar called Le Constellation in a resort in southwestern Switzerland.

Some of the victims are foreign nationals, said Stefan Ganzer, head of security for the canton of Valais. Authorities said 10 helicopters and 40 ambulances were mobilized.

Police earlier reported that many people had burns. Most of the wounded are in serious condition, said Mathias Reynard, the head of the cantonal government. The intensive care unit at Valais hospital was overcrowded and patients were transferred to other locations, he said.

Police said that the area was completely cordoned off and a no-fly zone was imposed over Crans-Montana, adding that the cause of the explosion remained unclear.

Later, the prosecutor's office clarified that the explosion was caused by a fire, not an attack. Authorities are currently trying to deliver the bodies of the victims to their families.