The ministry said a cafeteria for a local government district office in Chongqing city collapsed after a suspected gas leak and explosion, trapping a total of 26 people.
More than 600 first responders took part in the rescue mission and officials are investigating the cause of the explosion, it added.
China has been hit by a number of gas explosions in recent years. In October, four people were killed and more than 30 injured when a blast ripped through a restaurant in the northeastern city of Shenyang.
In June, at least 12 people were killed in a huge explosion in central Hubei province.