A bus exploded in southern China on Monday night, injuring 12 passengers and three passers-by, Chinese media reported on Tuesday.

Passengers escaped through the vehicle’s windows as the bus erupted into a ball of fire in Leshan, Sichuan province, at around 6.30pm, throwing nearby pedestrians to the ground, according to footage aired by state broadcaster CCTV.

Leshan Public Security Bureau said they were investigating a 31-year-old male suspect but did not elaborate.

All 15 of the injured were being treated in hospital, with one in a serious but not life-threatening condition, The Beijing News reported.

In the footage, the bus stopped on the wrong side of the road before being engulfed in flames.

Several eyewitnesses said they heard a loud noise before the explosion, Chengdu Business News reported.