At least two people were injured and "a number" of people buried when an avalanche swept down a ski slope in Andermatt, Switzerland, state police said Thursday.
"We believe there are more people buried but we can't say how many," Reto Pfister, state police spokesperson in the Swiss canton of Uri, told NBC News.
The police first received reports of the avalanche at 10:50 a.m. (4:50 a.m. ET). Emergency services including Alpine Rescue Switzerland, Swiss Air Ambulance and the state police were involved in the ongoing rescue operation.
A video posted on the Swiss news website site Blick showed a swath of snow careen down the mountain into the path of skiers who were then buried by the powder.
The two people who were rescued were hospitalized with minor injuries, Pfister said.
According to the Institute for Snow and Avalanche Research, the area has an avalanche a danger level of three out of five.
Out of 13 ski lifts in Andermatt, seven were open on Thursday, according to Skiresort.info.
Andermatt, located nearly 70 miles south of Zurich, is popular with skiers from around the world.