A fire ripped through a crowded bar in the luxury Swiss ski resort town of Crans Montana on New Year's Eve, killing and injuring several people, police said early Thursday.
As revellers rang in the new year, a "fire of undetermined origin" broke out in a bar popular with tourists, police in the Wallis canton in southwestern Switzerland, police said in a statement.
"Several people lost their lives and others were injured," the statement said, describing the incident as "serious" and said "a major emergency response is underway".
"A large contingent of police, firefighters, and rescue workers immediately went to the scene to assist the numerous victims," it said.
"The operation is still ongoing."
Swiss daily Blick cited a doctor at the scene suggesting that the death toll could be in the "dozens".
Regional daily Le Nouvelliste also said its sources were describing "a heavy toll", with "around 40 dead and 100 injured".
Images published by Swiss media showed a building in flames, and people screaming and running in the dark.
Swiss media suggested that the fire may have started when pyrotechnics were used during a concert, but police siad the cause was unkown.
Police spokesman Gaetan Lathion told AFP earlier there had first been an "explosion of unknown origin".
He said the explosion took place at around 1:30 am (0030 GMT) in a bar called Le Constellation, where more than 100 people had gathered for New Year celebrations.
Several hours after the blast, an AFP photographer saw a number of ambulances on the road from Crans Montana.
Police said the areas was "completely closed to the public", and that "a no-fly zone over Crans Montana has been imposed".