VALLETTA, Malta (AP) — Police in the Maltese capital of Valletta say 71 people have been injured when a glass banister in a nightclub collapsed as scores of people were trying to leave at the same time after experiencing difficulty breathing.

The banister shattered under their collective weight early Sunday, with many falling the height of a one-story building. Injuries included fractures and cuts from glass shards.

The health parliamentary secretary, Chris Fearne, told reporters that two girls, ages 13 and 15, were critically injured, while 15 others are being treated in the hospital.

Police are investigating a possible gas leak. Prime Minister Joseph Muscat expressed concern that laws regarding age limits in nightclubs were not being observed, promising tough action by the government. The minimum age for entering nightclubs is 17.