Two mountain guides acquitted of involuntary manslaughter will have to return to court after the army prosecutor Maurus Eckert appealed the verdict on Wednesday.
On Friday a Swiss military court acquitted the two guides, who led an army ascent of the Jungfrau mountain that ended in the death of six recruits in July 2007.
The defendants were awarded damages by the court in Chur in eastern Switzerland. They faced up to three years in prison if found guilty.
The court awarded SFr75,000 ($75,000) to the 47-year-old guide and SFr90,000 to his younger colleague.
The defence argued that the accusation of negligence had not been sufficiently backed up, pointing to the evidence of experts who said that the danger of avalanche was limited rather than pronounced.
Furthermore, the defence said it was entirely possible that one of the recruits had tripped and pulled the ropes in his fall, which would mean the avalanche had not been the risk factor.
The six who died fell 1,000 metres down the flanks of the 4,158-metre peak in the Bernese Alps, and were carried away by an avalanche the group is said to have triggered itself. Six soldiers and the two guides escaped unharmed.
The army was exposed to harsh criticism following the Jungfrau deaths and a river rafting accident on the Kander a year later that cost the lives of five soldiers.
No date has been set for the new trial.
swissinfo.ch and agencies