Geneva: Several people have died and multiple others sustained injuries after a Dutch tour bus plunged down an embankment in eastern Switzerland on Thursday.

The accident occurred around 4:45 pm (1445 GMT) on a road between the communes of Susch and Zernez in the canton of Graubunden. According to local police, the vehicle struck a safety barrier, overturned, and fell off the roadway. Rescue teams and helicopters were deployed to the scene, as shown in local media coverage.

The Dutch Federation of Travel Agencies (ANVR) confirmed that the coach was operated by the travel firm Oad and had 48 Dutch passengers on board. The group had departed the Netherlands on Monday and was conducting a day excursion into Switzerland from Austria.

Swiss officials confirmed the incident on social media but withheld specific casualty numbers to prioritize notifying relatives.

"Several people died in the coach crash in Susch. Several others were also injured," the cantonal police said on X, without giving details on the circumstances of the accident or the victims' identities.

A spokesman for the force added that a detailed toll would not be made public until families were informed.

Following the crash, Oad expressed shock at the incident.

"Our thoughts are with everyone involved and their loved ones. Local authorities are currently fully engaged in relief efforts and in determining the situation and the number of casualties," it added.

"We are doing everything in our power to obtain clarity quickly and to support those involved and their families wherever possible."

Swiss President Guy Parmelin offered his condolences to the families of the victims, calling the crash a "tragic accident".

The crash site lies near Zernez, the main access area for the Swiss National Park in the Engadine valley. (AFP)