By Cecile Mantovani and Dave Graham

CRANS-MONTANA, Switzerland, Jan 5 (Reuters) - Pressure was building for answers on Monday from the investigation into a New Year bar fire in a Swiss ski resort that killed 40 people, after authorities said they had now identified all the victims, most of whom were teenagers.

The Alpine getaway of Crans-Montana in the canton of Valais united in mourning on Sunday with condolences coming in from leaders ranging from Pope Leo to Chinese President Xi Jinping.

Prosecutors said the fire that spread rapidly in the early hours of January 1 was likely caused by sparkling candles igniting the ceiling of the bar's basement.

CRIMINAL INVESTIGATION

Authorities are investigating the two people who ran the bar on suspicion of crimes including homicide by negligence. On Sunday, police said circumstances did not currently merit them being put under arrest and they did not see a flight risk.

On Monday, Swiss newspaper Blick said anger over the case was growing.

"Why are the couple running the bar free?" the paper said on its front page, pasted over a photo of mourners and media gathered around the huge pile of flowers left in front of the "Le Constellation" bar.

The youngest victims of the blaze, which also injured 116 people, were only 14 years old, and the dead were from all around Europe, including several from France and Italy.

Swiss police, who have not named the victims, said on Monday they had now identified all the injured as well.

ITALIAN REPATRIATIONS

Italian Deputy Prime Minister Matteo Salvini said in a social media post that "in civilized Switzerland, the prison gates will have to open for quite a few people".

Salvini said there had been a failure to ensure the bar's basement was safe, questioning the emergency systems and whether there had been enough inspections.

Crans-Montana will on Friday hold a ceremony honouring the victims. The French government said that President Emmanuel Macron would attend.

Italy on Monday repatriated five of the six Italians who died in the fire, the Italian government said.

A military plane took to Milan the bodies of Achille Barosi and Chiara Costanzo from Milan, Giovanni Tamburi from Bologna and Emanuele Galeppini from Genoa. Military personnel saluted their coffins as they were carried from the plane.

The body of Riccardo Minghetti was due to fly on to Rome. The sixth Italian victim, Sofia Prosperi, lived in Switzerland and would be buried there, the Italian government said.

SILENT PROCESSION

Aika Chappaz, a local resident who took part in a silent procession through the town on Sunday, said justice must be done for the sake of future generations.

"It's crucial that such a tragedy never happens again. And the investigation must be thorough, because it's so unbelievable," she said.

Tages-Anzeiger, another leading Swiss newspaper, said questions must be answered about the age checks at the bar, the soundproofing material used in the basement and the standards governing use of the so-called fountain candles.

One of the bar's two operators, Jacques Moretti, told Swiss media that Le Constellation had been checked three times in 10 years and that everything was done according to the rules.

Valais authorities said investigators were checking if the bar had undergone its annual building inspections, but that the town had not raised concerns or reported defects to the canton.

The municipality of Crans-Montana said it has handed prosecutors documents relevant to the investigation and had joined the criminal proceedings as a civil party.

"This will allow (the municipality) to actively contribute to establishing all the facts," it said.

(Reporting by Dave Graham and Cecile Mantovani; Additional reporting by Elizabeth Pineau in Paris, Crispian Balmer in Rome, Emma Farge in Geneva and John Revill in Zurich;Editing by Alex Richardson)