At least 27 people were killed and dozens more injured after a devastating fire ripped through a popular pub in the Thai capital late Sunday, trapping patrons inside and raising fresh concerns over fire safety standards at entertainment venues.

The blaze broke out shortly before midnight at the Rong Beer Na Lat Phrao pub in Bangkok's Chatuchak district. Firefighters managed to bring the flames under control within about 30 minutes, but thick smoke had already engulfed the building, causing heavy casualties. 

Bangkok Governor Chadchart Sittipunt said 63 people were taken to hospitals, including 22 who remained in critical condition. Emergency workers found many victims clustered near the pub's restrooms, where they had apparently sought refuge after smoke rapidly filled the venue. 

Thai Prime Minister Anutin Charnvirakul visited the scene on Monday and confirmed the death toll, describing the incident as a national tragedy.

He ordered a full investigation into the cause of the fire and instructed authorities to determine whether the venue had complied with fire safety regulations. 

Witnesses described scenes of panic as a power outage was followed by what appeared to be a loud explosion near the stage, plunging the pub into darkness before flames spread rapidly through the building.

A member of the band performing at the venue told Reuters that electricity suddenly failed moments before a powerful blast sent customers scrambling for safety. Many were unable to locate exits amid the dense smoke. 

Firefighters said the blaze itself was relatively manageable, but the smoke spread with alarming speed throughout the enclosed space, leaving many patrons overcome before they could escape.

Rescue workers continued searching the charred building into Monday morning while forensic teams worked to identify victims. 

Authorities said the pub possessed the necessary operating permits and designated emergency exits, but investigators will examine whether evacuation routes were accessible when the fire broke out. Officials have yet to determine the exact cause of the blaze. 

The tragedy is among Thailand's deadliest entertainment venue fires in recent years and has revived painful memories of previous nightclub disasters that prompted calls for stricter enforcement of building and fire safety regulations.