Davos, Switzerland
There was a "small explosion" on Thursday at the Hotel Post Morosani in Davos, Switzerland, which hosts high-powered annual World Economic Forum this week, police said.
Fon Mahturos, a spokesman for the WEF, said that "a small firework exploded at the rear entrance of the Hotel.
Former U.S. President Bill Clinton is scheduled to attend an evening of celebration Thursday at the hotel, one of the most prestigious Davos.
A window was damaged, and the police investigator. The hotel is fully operational and available Mahturos said.
There were no reports of injuries.
Someone at the hotel for a meeting said that the explosion was so insignificant that most of the guests and visitors are unaware that something had happened.
Swiss media say an anti-WEF had threatened in an email to the hotel attack with fireworks.
The Swiss newspaper Tribune de Geneve said the hotel is used by the Swiss government in the forum.