Five people are missing and eight others injured after a restaurant with apartments was "completely destroyed" by fire in the Swiss town of Thusis, police have said.

Initial investigations indicate the blaze broke out on the second floor and the cause was still being investigated, according to the Graubünden cantonal police.

The force said it was called just after midnight local time (22:00 GMT on Thursday) and that nearly 100 firefighters responded. The roof had to be opened using a crane after the stairwell collapsed.

The Alpine Graubünden region, also known as Grisons, is a popular holiday destination for both winter sports and summer nature activities in eastern Switzerland.

Fourteen people escaped the building, police said, of whom two were seriously injured, two suffered moderate injuries and four suffered minor injuries.

People were taken to hospitals in neighbouring Chur, Thusis, Ilanz and Zurich, it added.

Police and the public prosecutor's office are investigating the cause of the fire.

A number of foreigners were staying in the building at the time, a cantonal police spokeswoman told Switzerland's Keystone-SDA news agency.

Firefighters and emergency service personnel are now removing the roof layer by layer to access the collapsed stairwell, as the search for the missing people continues.

If human remains are found, DNA samples will be taken for identification, the spokeswoman said. The search could last for days, she added.