(CNN) -- Twelve people died when a large gas cylinder exploded Thursday on the roof of a restaurant in Doha, Qatar, the emirate's civil defense director said in a televised news conference.
The blast injured 31 others and caused the partial collapse of Istanbul Restaurant, civil defense director Hamad Othman N. Al-Duhaimi said.
The collapse injured customers, employees and some people walking past the restaurant, Al-Duhaimi said. It also damaged nearby buildings and cars near the restaurant, which is close to the city's popular Landmark Mall.
The force of the blast spread 165 feet (50 meters), Qatar's Interior Ministry said on Twitter.
It's not known at this time what caused the gas cylinder to explode. Authorities were investigating, the ministry said.