Swiss police have launched an investigation after a small explosion in a hotel store room during the Davos world economic forum (WEF).

The blast shattered two windows but caused no injuries at the Post Hotel Morosani shortly after 0900 (0800 GMT).

Police could not say immediately what was the source of the explosion.

According to Swiss media, anti-WEF activists say they attacked the hotel with a firework device.

The Post Hotel Morosani is just over 1.5km (one mile) from the annual forum's venue.

With 2,500 political and business leaders attending the summit, security in the small Swiss resort has been tight, BBC reported.