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 operations.

Search teams respond to an avalanche at a ski resort in Andermatt, Switzerland on Thursday. Ski Academy Andermatt

A video posted on the Swiss news website site Blick showed a swath of snow tumble down the mountain into the path of skiers who were then buried by the powder.

The two people who were rescued were flown by air ambulance to the hospital with minor injuries, said Mathias Gehrig, a spokesperson for Swiss Air Ambulance, which sent three rescue helicopters to the scene.

Four others were rescued or freed themselves from the avalanche without injury, according to a police statement.

"The longer the search takes, the smaller the chance they get away without an injury or danger to life," he said.

Anne Jehn, director of Andermatt Ski Academy, was on the scene just after the avalanche hit and worked with her students to rescue a woman from the snow.

"She was ash gray. Shocked. But I guess she'll be okay," Jehn said in a private message on social media.

According to the Institute for Snow and Avalanche Research, the area has an avalanche danger level of 3 out of 5.

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Out of 13 ski lifts in Andermatt, seven were open Thursday, according to Skiresort.info.

Andermatt, located nearly 70 miles south of Zurich, is popular with skiers from around the world.

This was not the only avalanche to occur in Europe on Thursday.

In Austria, three avalanches came down in Ankogel in the province of Carinthia, an Austrian police spokesman said, according to Reuters.

One happened outside the secured ski slope and buried two free riders who were able to free themselves.