A massive inferno set a hotel-casino in Cambodia ablaze for over 12 hours on Thursday, killing at least 19 people and injuring over 60, authorities said.

There are still many guests and staff of Grand Diamond City casino and hotel who have not been accounted for, the Associated Press reported.

The fire was serious enough that Thailand, which borders the town of Poipet where the hotel is located, assisted with fire trucks and emergency crews.

Victims are still believed to be trapped under the debris of the charred building or possibly stuck in rooms that rescuers have not been able to enter.

Sek Sokhom, the head of Banteay Meanchey province's information department, announced that the number of dead is expected to increase.

Videos posted to social media showed guests of the hotel jumping from a roof after being trapped by the blaze. Another video posted by Cambodia's fire department contained footage of witnesses begging firefighters to rescue dozens of people stuck on the roof of the hotel, which is over 12 stories tall at its peak. One of them fell off the roof as it caught on fire.

Most of the victims were Thai, Chinese, Malaysian, Vietnamese and Cambodian, Sokhom said. Bodies of the deceased were being taken to an area Buddhist temple.

Cambodia’s Department of Fire Prevention, Extinguishing and Rescue said that hotel guests were trapped in the 13th to 15th floors and were calling for help from windows at around 4 a.m.

"The fire was massive, and was inside the casino, so it was difficult for our water cannons to reach it," a firefighter said in footage posted online by the fire department.