Teen critical after Sydney car explosion

A teenager is in an induced coma and a man is injured after a gas bottle exploded in a car in Sydney's southwest.

Emergency services were called to Fairfield about 5.30pm on Sunday where a car was found alight after a gas bottle, which was in the boot, exploded when the driver lit a cigarette.

A 15-year-old boy, who was walking past the car, suffered critical injuries and has been placed in an induced coma, while the driver, whose age is unknown, has been treated for serious burns at Liverpool Hospital.