A fire broke out early Friday morning inside a nightclub in Thailand's eastern Chonburi province, causing at least 13 deaths and 35 injuries, a police official said.

The cause of the fire is unknown, and all identified victims are Thai nationals, according to authorities. Separately, the Chonburi emergency services described fourteen of the injuries as being severe.

The fire at the Mountain B nightclub began at 1:00 a.m. local time, Wuttipong Somjai, superintendent of the local police station, told Reuters by phone. The nightclub is located approximately 180 kilometers southeast of Bangkok.

Local television footage depicted people fleeing the blaze, firefighters extinguished flames, and emergency personnel sifting through the charred structure, littered with shoes and bottles.

A witness named Nana told local television that she was with five companions when the fire broke out.

"I observed flames above the right half of the stage. "I believe it was around the same time that the singer on stage saw it and yelled "fire!" and threw the microphone at it," she told PPTV. Inside the bar, I observed many bouncers coated in flames.

Thirteen years ago, pyrotechnics ignited a fire at a New Year's Eve celebration at Bangkok's crowded Santika nightclub, killing 66 people. Investigations into that fire uncovered several significant safety violations at the club, evidence of official corruption, and weak attitudes toward safety at entertainment venues at the time.

Friday, Prime Minister Prayuth Chan-Ocha told the victims' relatives that they would receive assistance from the authorities and asked entertainment venues around the nation to ensure that they had emergency exits and safety measures in place.