All 20 people on board an old-time propeller plane were killed Saturday after the aircraft crashed in the Swiss Alps, authorities told Swiss media on Sunday.
Police spokeswoman Anita Senti told reporters that it was with "sad certainty" that "the 20 people aboard perished".
Authorities have provided few details about those on board JU-Air's plane which crashed on the west side of the Piz Segnas mountain in the canton of Graubuenden on August 4.
Officials said 11 men and nine women were killed, most from Switzerland but also a couple and their son from Austria.
The wreckage of the plane was in a basin at 2,450 metres (8,000 feet) above sea level surrounded on three sides by peaks, a Reuters witness said.
In another crash over the weekend, a family of four including two young children were killed when a small plane came down in central Switzerland.
Mesut Ozil has respect of every player, says Arsenal boss
The new Arsenal boss sent a message to Ozil in the wake of his global retirement. Ozil, took to his social media accounts, to put across his decision on Sunday.
Officials said Sunday the vintage aircraft appeared to hit the ground near-vertically and at a high speed.
The plane did not catch on fire before or after it hit the mountain, and investigators have not found any signs the aircraft lost parts or broke up in the air before the crash, Knecht said.
Twenty people are confirmed dead after a vintage World War II aircraft crashed into a Swiss mountainside, police reports said. They also expect the investigation into the cause of the crash to be "relatively complex".
The area around the crash site, which is popular with hikers and skiers and includes a glacier, was closed to the public.
Almost 5,000 Ju-52 planes, a product of Germany's Junkers, were manufactured between 1932 and 1952. Its pilots are ex-military and professional pilots, all volunteers. Knecht said that while heat can affect an aircraft's performance, experienced pilots could deal with that. It has suspended all flights until further notice. "The JU-Air team is deeply saddened and thinks of the passengers, the crew and families and friends of the victims", the company said in a statement on its website.