(ISTANBUL) — A fire at an Istanbul nightclub during renovations on Tuesday resulted in at least 29 deaths, officials and reports said. Several individuals, including managers of the club, were detained for questioning.

At least one person was receiving treatment at a hospital, according to a statement from the Istanbul governor’s office.

The Masquerade nightclub, which was closed for renovations, was located on the ground and basement floors of a 16-story residential building in the Besiktas district on the European side of the city divided by the Bosphorus. The fire had been extinguished.

Gov. Davut Gul told reporters at the scene that the cause of the fire was under investigation and the victims were believed to be involved in the renovation work.

Authorities detained five individuals for questioning, including managers of the club and one person in charge of the renovations, according to Justice Minister Yilmaz Tunc.

Mayor Ekrem Imamoglu said authorities were inspecting the entire building to assess its safety.

Several firefighting and medical teams were dispatched to the scene, he said.