South Korean police rounded up 24 members of a voice phishing gang based in China and arrested 18 suspects in the group.
The arrests come after South Korean President Moon Jae-in called for tougher measures against fraudulent phone calls and text messages in June.
Busan Police Agency said Tuesday the phone scammers had committed financial fraud and stole more than $1.7 million from South Korean victims, CBS No Cut News and Newsis reported.
The suspects allegedly began operating a call center in January 2015, closing it in May of that year after defrauding more than 300 South Koreans of their savings and assets, police said.
The scammers operated out of Huizhou, in China's Guangdong Province, in a residential apartment. A "general manager" recruited the team, and the suspects took turns initiating scams, police said.
Phone scams are a serious problem in Korea, usually involving cybercriminals targeting unsuspecting victims with demands for cash and false offers. Senior citizens and individuals with outstanding debt have often been targets.
Scams originating from China and targeting South Korean mobile phone owners have been on the rise. Criminals typically trick their victims into thinking they are in financial trouble, or that they are already targets of scams that the criminals can "resolve" for them if they follow instructions by phone.
Other tactics include instructing victims to install a mobile app that contains malware. Some scammers offer low-interest loans, targeting people with outstanding loan payments. The data on individuals with loans is obtained illegally, according to the South Korean press report.
Chinese nationals speaking in Korean over the phone have previously been arrested after attempting scams. Phone scammers have been known to make strange requests, including asking their targets to place their life savings in a refrigerator, according to a 2019 report from CNN.
From January to October 2019, more than 31,000 phone scams were reported in Korea, costing victims about $429 million. (UPI)