Dec. 26 (UPI) -- Swiss rescuers searched for multiple skiers who may have been buried in snow after an avalanche Thursday at a ski resort.
The avalanche occurred around 10:50 a.m. at the SkiArena resort in Andermatt, a village in the Swiss Alps, police said in a release.
Six people were either rescued or freed themselves from the snow. Emergency officials transported two people by air ambulance to a hospital for minor injuries, Swiss Air Ambulance spokesman Mathias Gehrig said.
Police said the four others were uninjured.
The rescue teams do not believe others were trapped in the snow, the ski resort said on its Facebook page, adding that the cause of the avalanche was under investigation.
"According to the internal piste security evaluation process, the slope was classified as safe," the ski resort said. "Why the avalanche has come down is part of the ongoing investigation by the cantonal police."
Police said it was a snow glide avalanche. According to the Colorado Avalanche Information Center, this type of avalanche occurs with the entire snow cover is released and glides down the mountain.
The resort planned to keep the ski slope closed through Friday.