The accident happened at about 4.45pm between the communes of Susch and Zernez in the far-eastern canton of Graubunden.
The coach hit a safety barrier before overturning and plunging down an embankment, a local police spokesman told Swiss media.
The Dutch Federation of Travel Agencies (ANVR) said that the coach belonged to the tour company Oad and was carrying 48 passengers, all of them from the Netherlands.
“Several people died in the coach crash in Susch. Several others were also injured,” the cantonal police said on social media, without giving details on the circumstances of the accident or the victims’ identities.
