An additional group of up to six people have not been contactable since the landslide took place.
Graubünden cantonal police have released a statement naming German, Australian and Swiss citizens as those among the missing.
The landslide took place in Bondo, a village near the Italian border, at approximately 9:30am local time on Wednesday, August 23.
According to local authorities, at least four million cubic metres of mud and rock slid down the Piz Cengalo mountain.
Bondo was completely evacuated, thanks to an alarm system installed after a landslide in 2012. The village will remain closed until at least Friday.
More than 100 rescuers are working to find those reported missing, utilising helicopters and inferred cameras.
The landslide stretched across 3 miles and was more than 10 metres high in places according to local police.