SEOUL - Nine people were killed and 25 others injured in a fire at a karaoke bar in South Korea's southern port city of Busan, local authorities said Sunday.

The fire took place at around 8:55 pm local time Saturday. According to local police, the fire broke out in a singing room located in the third floor of a six-story building in downtown city, and the heavy smoke immediately spread to the whole floor.

Dozens of people fled outside or to the top of the building when the fire started and were rescued later. However, 9 people failed to escape and were killed in the fire.

Among the dead there are three Sri Lankans. Most of the victims are young people in their 20s or 30s, who died of inhaling toxic gases.

Authorities suspect a gas explosion may have caused the fire, but are making an further investigation to determine the cause of the fire.