LANZHOU -?The number of students in a critical condition rose to 37 after a fire drill went wrong in a high school in Northwest China's Gansu province, local authority said Wednesday.

A total of 191 students have been hospitalized, according to the latest statement by the Tianshui government.

On Sept. 18, 412 students from a junior middle school in Tianshui City participated in a drill, which involved firing smoke guns to simulate fire. Many students began to cough and vomit after inhaling the smoke.

An expert panel dispatched by the National Health and Family Planning Commission arrived in Tianshi on Monday to assist in the treatment.