Survivors of the car bomb attack at a Hat Yai hotel in Songkhla on Saturday are complaining about poor safety systems at the hotel.
The city mayor, meanwhile, has apologised for the poor emergency response.
Sonthaya Pimsiri was watching an action film in a 3-D cinema on the fifth floor of the Lee Gardens Plaza Hotel when a car bomb in the hotel's car park went off.
Mr Sonthaya, a 54-year-old primary education official from Phatthalung province, said while he was watching an explosion scene in the movie, the real explosion in the car park took place.
The impact lifted his body off his seat. A second later, the cinema blacked out as electricity supplies were severed.
As ushers opened the doors of the cinema, he heard people outside shouting that a bomb had gone off.
A warning of a possible second bomb blast delayed attempts by crowds in the cinema to flee. Thick clouds of smoke entered as hundreds of people scrambled for the fire exit. "People were running for their lives as they were running out of air," he said.
"There were windows along the fire exit but I could not break them. It was difficult to breathe as the place was filled with smoke," Mr Sonthaya said.
Fortunately, windows on the first floor were broken and people inside were able to breathe through the holes.
He said the building's occupants made their way out, their faces blackened by thick smoke.
Mr Sonthaya complained the building lacked sprinklers and fire alarms. The fire exit was narrow, and unventilated. "The security system at the hotel was very poor," he said.
"Security guards were too lenient about checking vehicles which entered the underground car park. They should have also opened the doors of the vehicles, not just checked their boots," he said.
Thaksa-on Dechawanto, a 32-year-old vendor, said the first floor where she sells goods was packed with shops, but lacked a water sprinkler.
"Without a good safety system, I will not rent space there again," Mrs Thaksa-on said.
Hat Yai mayor Prai Pattano said the bomb's strength was unprecedented for Hat Yai.
Local authorities assumed initially that a gas pipe had exploded. The response by emergency services was slower than it should have been.
'We had no rescue plan for such an emergency situation and the rescue mission was not quick enough.
"I must apologise and will take this as a lesson to prevent such an incident from recurring," Mr Prai said.