A storm has killed three and injured some 40 people at a music festival in the eastern Belgian city of Hasselt on Thursday, said the Hasselt mayor.

Festival-goers leave the venue of Pukkelpop open-air music festival when festival cancelled after a storm collasped a stage near Hasselt, eastern Belgium, August 18, 2011. A storm has killed three and injured some 40 people at the music festival in Hasselt on Thursday, said the Hasselt mayor. (Xinhua/Wu Wei)
"The Pukkelpop festival has killed three and injured 40," Hasselt mayor Hilde Claes told local TV station.

Eleven of the injured are in critical situations, according to the mayor. Police has cordoned off the site.

A witness, who managed to have come home told Xinhua earlier that at least six people were killed.

The witness, a young man in his twenties said that his younger sister was still trapped in the gymnasium where the Pukkelpop music festival was held.

Strong wind and torrential rain knocked down a tree, which fell on the stage at the festival Thursday afternoon, said the young man, whose parents declined to disclose his name.

A total of 40,000 audience were present when the storm hit, most of whom are youngsters. The stormy weather also caused a traffic jam of more than 200 km in the afternoon and in early evening across the country.

VietNamNet/Xinhuanet