Just because someone is friendly and offering you money doesn’t mean they are your friend. As a good example of that lesson, visitors to casinos located in the Philippines should be wary strangers offering loans, the National Bureau of Investigation (NBI) warned on June 7, as reported by the government outlet Philippine News Agency.

Specifically, there’s a risk that gamblers, and particularly tourists, might be kidnapped if they are unable to pay back their loans. Ferdinand Lavin, an NBI spokesperson, advised the public that if a money lender approaches them, “people playing in casinos should approach the hotel staff and security for help immediately.”

This reminder comes fresh off of the arrest of six suspects, five Chinese and one Filipino-Chinese, on charges of kidnapping and holding three people in Parañaque City, an area of the Metro Manila area in close vicinity to the Entertainment City. They were demanding their hostages pay PHP7 million ($130,000), the amount of their loan plus interest.

Three of the suspects were arrested in a sting operation. The other three tried to spring their friends from jail by offering a large bribe to the NBI Cyber Crime Division, and were then also arrested.