A fire at a bar in a Swiss ski resort appears to have been caused by sparklers placed on bottles of champagne that came too close to the ceiling, authorities said.

Forty people died after the blaze in the early hours of New Year's Day in Crans-Montana, while 119 were injured.

Valais Attorney General Beatrice Pilloud detailed at a news conference that the investigation will focus on the materials used on-site, the bar's fire safety measures, its capacity, and the number of revelers present during the incident.

Everything leads us to think that the fire started from sparkling candles - or sparklers - which were put on bottles of champagne [that were] moved too close to the ceiling. From that, a blaze began very quickly, Ms. Pilloud announced.

As formal identifications of the deceased are underway, it is revealed that 113 of the injured have been identified so far, including several international citizens. Among them is 19-year-old footballer Tahirys Dos Santos, who was gravely injured and airlifted for urgent treatment.

The bar, known as Le Constellation, has been a longstanding venue with the capacity to hold up to 300 individuals. Families have gathered nearby, mourning their lost loved ones and laying flowers at makeshift memorials.

A regional president indicated that many injured parties are being treated in specialized centers for severe burns across Europe, and an official ceremony for mourning will occur on January 9.