Two Portuguese nationals are among the eight people injured in the major fire that destroyed a building housing a Portuguese restaurant in Switzerland, Portugal’s Foreign Ministry has confirmed.

One of the Portuguese victims was seriously injured, while the other suffered minor injuries, the ministry said on Friday.

“The Ministry of Foreign Affairs is following with consternation the fire at the Portuguese restaurant Beverin in Switzerland,” it said in a statement to state-owned news agency Lusa.

The identification of those affected is still ongoing, meaning it is not yet known whether any Portuguese nationals are among the five people who remain missing.

The fire broke out shortly after midnight in Thusis, a small town in eastern Switzerland, in a building containing apartments and the Beverin restaurant.

According to Graubünden Cantonal Police, initial indications suggest the blaze started on the second floor before spreading through the building, which was completely destroyed.

Fourteen people managed to escape. Eight were injured: two seriously, two moderately and four with minor injuries. The victims were taken to hospitals in the region and to Zurich.

Almost 100 firefighters were deployed to tackle the blaze.

The intensity of the fire caused the building’s stairwell to collapse, forcing emergency crews to use a crane to open the roof.

Police and the Swiss public prosecutor’s office have opened an investigation to determine what caused the fire.