Four Vietnamese nationals were jailed on kidnapping charges in Svay Rieng province on Saturday after allegedly detaining two of their countrymen over gambling debts in a casino in Bavet town.

According to Bavet police chief Maophin Phirum, who did not name suspects, the victims were reportedly prevented from leaving a room rented at the Asia Casino, after it was discovered they were unable to repay a debt of 52 million Vietnamese dong – around $2,400 – loaned to them by the four suspects.

“They were forced to contact their families in Vietnam to ask for ransom money but managed to communicate about their detention to the casino owner, who reported it to police,” Phirum said.

The victims were named as Nguyen Than Nhek, 29, and Nguyen Nhek Hiep, 22.

Asia Casino is one of a cluster of casino-hotels located next to the Vietnamese border that cater to a largely Vietnamese crowd.

The incident is just the latest example of Vietnamese nationals being kidnapped over gambling debts racked up at Cambodian casinos.

Last year, four Vietnamese nationals kidnapped and tortured two Vietnamese in Preah Sihanouk province over a $14,000 debt.

In 2013, a Vietnamese farmer sustained serious head injuries and a broken ankle after falling from a second-storey window at the New World Casino in Bavet, after being detained for five days.