The death toll has risen to 24 in a massive blaze that engulfed a casino complex at the Cambodia-Thailand border, CNN reported on Friday citing the local authorities.

However, numerous people continue to remain missing after the blaze at the Grand Diamond City Hotel and Casino in Poipet, a city that borders Thailand.

The hotel employed an electric system for the rooms and elevators, so when the fire broke out and the building lost electricity, many guests were trapped in their rooms and were unable to escape, CNN quoted Sek Sokhom, the spokesman for the Cambodian province of Banteay Meanchey as saying.

The cause of the fire remains unknown and the Cambodian government has set up a committee to investigate, he added.

Notably, Poipet, a transportation centre between Bangkok, Thailand, and Siem Reap, Cambodia, is well-known for its numerous casinos and is home to a sizable Thai population that work in the city's gaming sector. Since nearly all types of gambling are prohibited in Thailand, many Thais cross the border to participate in legal gambling.

Rescue operations are underway.

(with inputs from ANI)