Several people were killed and others injured when an explosion ripped through a bar in Switzerland’s luxury Alpine ski resort town of Crans Montana, police said on Thursday.

“There has been an explosion of unknown origin,” Gaetan Lathion, a police spokesman in Wallis canton in southwestern Switzerland told AFP.

“There are several injured, and several dead.”

He said the explosion took place at around 1:30am (local time) in a bar called Le Constellation, which is popular with tourists, as revellers rang in the new year.

Images published by Swiss media showed a building in flames, and emergency services nearby.

“The intervention is still ongoing,” he said.

Citing police, Sky News reported that at least 10 people had died in the incident, with some local media saying the figure may be higher. Police declined to confirm the number, but said many people were being treated for burns.

The area has been completely closed off, and a no-fly zone has been imposed over Crans-Montana, police said, adding that the cause of the fire remained unclear.

More than 100 people were in the bar at the time of the explosion, Swiss media outlet Blick reported, citing police.

This is a developing story that is being updated as the situation evolves. Initial reports in the media can sometimes be inaccurate. We will strive to ensure timeliness and accuracy by relying on credible sources, such as concerned, qualified authorities and our staff reporters.