Forensic police officers inspect the site of a fire in Bangkok on Monday. BANGKOK METROPOLITAN ADMINISTRATION/AP

BANGKOK — An explosive fire at a pub in Thailand's capital Bangkok killed 27 people and injured dozens, officials said on Monday, with police investigating possible negligence including obstructed emergency exits as people scrambled to flee the burning venue.

One video of the incident posted on social media and verified by Reuters showed thick smoke billowing out of the Rong Beer Na Lat Phrao pub, before an intense horizontal plume of fire jetted out of a doorway, as screaming customers fled the premises around midnight on Sunday.

"Most of the victims ran to the back of the building, into the bathroom, and there was no clear sign of a fire exit," said Prime Minister Anutin Charnvirakul, who visited the site early on Monday.

According to the Bangkok Emergency Medical Centre, the number of injured people was 73, with 25 in critical condition. Bangkok Governor Chadchart Sittipunt said most of the deaths were caused by smoke inhalation and that the authorities are working on identifying victims as many did not carry ID.