BANGKOK: The majority of people killed in Bangkok's devastating bar fire died from smoke inhalation, forensic police told AFP on Friday (Jul 17) after completing autopsies of all 33 victims.

The blaze swept through the popular Rong Beer Na Lat Phrao restaurant and bar in the Thai capital on Sunday night, quickly engulfing the venue.

Autopsies found that 27 victims died from carbon monoxide and cyanide poisoning after inhaling smoke, according to Wiroon Supasingsiripreecha, commander of the Institute of Forensic Medicine.

The gases are produced by fires and "when inhaled, block oxygen from reaching the blood, resulting in death", he told AFP.

"If inhaled in large quantities, they can cause death within four minutes."

The remaining six victims died later in hospital from severe burn injuries, Wiroon said.

Authorities said the death toll on Friday remained at 33, with 77 people injured.

The bar owner was admitted to intensive care immediately after the fire, but it was not clear if he was still in hospital.

Senior police officer Siam Boonsom said on Thursday that investigators had found evidence the venue was using high-voltage electricity without approval, which could have been a factor in the fire.

In the wake of the blaze, police and Bangkok's governing body said they would inspect 1,000 entertainment venues across the capital within one month. 

Officials have so far ordered three bars to be temporarily closed for failing to meet safety standards.

Thailand's approach to health and safety regulations - particularly in bars and nig...