BANGKOK >> At least 13 people were killed and dozens injured when a fire broke out early Friday morning at a crowded music pub in eastern Thailand, police and rescue workers said.

Video circulating on social media showed people fleeing the pub while thick black smoke billowed from the door and then the entrance through which people were escaping was suddenly engulfed in flames. Several people’s clothing was on fire as they emerged from the pub. Rescue workers said more than three dozen people were injured.

The cause of the fire at the Mountain B pub in Sattahip district of Chonburi province, about 160 kilometers (100 miles) southeast of Bangkok, is under investigation, provincial police chief Maj. Gen. Atthasit Kijjahan told PPTV television news. He said the pub’s owner and staff were giving statements at the police station and the police forensic team would be collecting evidence at the scene. Police said the fire was reported around 12:45 a.m.

Several witnesses described seeing smoke and fire on the ceiling near the venue’s stage followed by the sound of explosions.

“The fire started at the top right corner of the stage,” a witness identified only as Nana told PPTV. “The singer must have seen it too, so he shouted ‘fire’ and threw away the microphone.”

“I am quite shocked. But I am lucky that when I saw the fire, I could get myself together and get out of there,” she said, adding that she saw several pub security guards with their clothing on fire.

A waitress at the venue, Thanyapat Sornsuwanhiran, also told Thai television reporters that she saw smoke near the stage.

“I shouted ‘fire’ to customers, and I was near the doors, so I directed them out. I kept shouting ‘fire, fire’ and the security guards were also helping lead people out,” she said.

Police chief Atthasit said the club had three entrances: at the front, on the side near the cashier for unloading goods and at the back. Thai public television station TPBS reported that the back door is often locked.

A DJ at the pub who did not identify himself told PPTV that the fire had spread quickly, in about a minute, when he heard the sound of an explosion, shattering windows.

The pub was lined with flammable soundproofing, and it took two hours for firefighters to put out the blaze, Manop Theprith of a private emergency services group told the television station. His group said 40 people were injured.

One of Thailand’s deadliest fires in recent decades was at a nightclub in the capital, Bangkok, during a 2008-2009 New Year’s Eve celebration, when 66 people were killed and more 200 injured. That blaze at the Santika nightclub also began on the ceiling above a stage, apparently sparked by an indoors fireworks display. Toxic smoke flooded the venue as the entire club caught fire.