All of the 40 victims who were killed in a bar fire in the Swiss Alps during New Year's celebrations have been identified, police in Switzerland said Sunday.

Twenty-six of the victims were under the age of 18, while two of those who lost their lives in the fire were just 14, officials said.

The fire on Thursday at Le Constellation in Crans-Montana is one of the worst disasters in Switzerland's history, President Guy Parmelin has said.

A vigil to honor the victims was held in the ski resort on Sunday.

The bar's owners, a couple, are under investigation for homicide by negligence, police have said.

What do we know about the victims?

According to Swiss police, 21 of the fatalities were Swiss nationals and seven were French citizens. One victim was a dual Swiss-French national, and a 15-year-old girl was a French, British and Israeli citizen. Six of those who died were Italian.

The deaths also included people with Emirati, Belgian, Portuguese, Romanian and Turkish nationalities.

Police have not released the identities of any victims. 

In addition to the 40 people who were killed, more than 100 were injured, many of them seriously. Thirty-five of the injured have been transferred to hospitals in Belgium, France, Germany and Italy.

Crans-Montana remembers the victims of the fire

At a small church just down the road from the destroyed bar, a service was held Sunday in memory of the victims.

After the service, the crowd moved to Le Constellation bar and the makeshift memorial next to it, with visitors applauding the emergency service workers in attendance.

Switzerland will hold a national day of mourning on Friday in memory of the victims, national president Guy Parmelin told local newspaper Sonntagsblick, adding that everyone in the country "can personally remember the victims."

Edited by: Karl Sexton