37 students are in a critical condition after a fire drill went wrong at a Chinese school.

A total of 191 students were hospitalised after school authorities decided to use fake smoke to make the drill more realistic, China's Xinhua news agency reports.

Students from the school in guangzhou province became ill immediately after the drill, some of them coughing and vomiting.

191 hospitalized, 37 in critical condition after fire drill goes wrong in Chinese school #XinhuaTV pic.twitter.com/EMgxaD0MC1

— China Xinhua News (@XHNews) September 24, 2015