By Kwang Jiraporn Kuhakan

POIPET, Cambodia (Reuters) -Cambodian rescue teams recovered several bodies on Friday from the charred rooms of a casino-hotel where a fire killed at least 27 people a day earlier, with more than 20 people still missing.

About 400 employees and patrons were in the Grand Diamond City casino and hotel in Poipet, a town on the Thai border, when the fire broke out in the early hours of Thursday, leaving the building gutted by the afternoon.

It was unclear what started the blaze but Sek Sokhom, head of the Banteay Meanchey provincial information department, said it may have been due to an electrical short circuit. An investigation was underway.

Authorities said they had to move slowly through the smouldering remains of the building in case it collapsed.

Dozens of rescue workers lined up outside the site on Friday, taking turns to go through the building room by room, while heavy machinery was used to clear blackened debris, video footage shared by a Thai volunteer rescue organisation Ruamkatanyu Foundation showed.

One survivor recounted seeing a light fixture throw off sparks that caused flames that reach the ceiling.

“Then it started getting chaotic. After the fire hit the ceiling, I don’t think it was ok,” Piyapol Sukkaew, a patron who was on the casino floor at the time, told Thai broadcaster Channel 7.

“It had gone on for half an hour and the fire trucks hadn’t arrived. After just five minutes, there was smoke everywhere.”

Cambodian Prime Minister Hun Sen on Friday expressed condolences for the victims and their families, and urged authorities to improve fire safety and response times.

Safety standards in Cambodia and other parts of Southeast Asia can be well below international standards and poorly enforced.

Chanathip Khokmanee, a provincial official in Sa Kaeo on the Thai side of the border said hospitals there had treated at least 112 people with injuries like burns, broken bones and respiratory problems.

Many of the victims were Thai, rescue workers said, and dozens of injured people were taken over the border to the Thai province of Sa Kaeo for treatment.

A key part of Cambodia’s tourism industry, casinos in the capital of Phnom Penh and on the borders with Vietnam and Thailand are a draw for visitors from Asian nations that ban gambling.

Those in Poipet employ Thai staff and are hugely popular with short-term Thai visitors as gambling is illegal across the border and unlicensed casinos operate underground there.

(Additional reporting by Chayut Setboonsarng in Bangkok, Prak Chan Thul in Phnom Penh; Writing by Kanupriya Kapoor; Editing by Stephen Coates, Martin Petty)

---