A fire at a discotheque and Karaoke bar in Medan, the capital of North Sumatra province of Indonesia, killed 20 people and injured 5 others on Friday night, secretary of the provincial administration Edy Sofyan said on Saturday.

The secretary said that an electrical short-circuit was suspected as the cause of the fire, which resulted in a heavy smoke in the room, but the police are still investigating the accident.

"The smoke made the visitors unable to breathe and killed 20 of them on the site," he told Xinhua over the phone from Medan.

The injured people had received medical treatment, said Sofyan.

He said the fire started at about 8 p.m. local time Friday, and firefighters put it out in about half an hour.