SEOUL -- A fire broke out Thursday afternoon in a subway train in Busan, South Korea's southern port city, injuring four people, YTN and Yonhap News Agency reported.

A train of the Busan subway Line No.1 caught fire at about 5:41 p.m. local time as air conditioners were on fire for unknown reasons.

The fire was extinguished completely 10 minutes later, but four passengers sustained minor injuries for poisonous gas inhalation and bruises caused when they ran away hurriedly and fell down on the ground. They were taken to a nearby hospital.

Some 400 passengers were evacuated right after the fire broke out, and no more casualties were reported as the fire stuck on no other places.