A power bank exploded, causing a fire on a subway train in China.

A female passenger's rechargeable battery pack caught fire inside a Line 3 train at Changsha University Station in Hunan Province.

Onlookers said the frantic commuter immediately removed her burning hooded jacket and dropped it, along with her bag, to the floor on November 9.

Footage shows another traveller stomping on the black sweater to extinguish the flames, while thick smoke from the blaze and a fire extinguisher billowed into the carriage.

Meanwhile, shocked fellow passengers looked on as the man continued to step on the damaged clothing.

Local media reported that another train rider hit the emergency brake to stop the locomotive before the fire could be fully extinguished.

No one was reportedly injured.

Lithium batteries, like those in power banks, have been linked to multiple fire-related incidents on trains, cars, and planes.

Experts believe that when a lithium battery fails, it can undergo thermal runaway, a rapid, violent reaction in which one or more cells rupture. This releases toxic, flammable, and explosive gases, creating an intense, self-sustaining fire.

The Changsha Rail Transit Prohibited and Restricted Carrying Catalogue allows power banks and lithium batteries with clear identification and a single product rating of no more than 160Wh to be carried into stations, but the total number must not exceed three.