SEOUL, South Korea (AP) — Dozens of South Koreans allegedly involved in online scams in Cambodia arrived in South Korea on a chartered flight Saturday to face criminal investigations.

The repatriation follows the death of a South Korean student who was reportedly forced to work in a scam center in Cambodia. His death triggered public outrage in South Korea, prompting the government to send a delegation to the Cambodian capital, Phnom Penh, for talks on joint responses.

Cambodian Interior Ministry spokesperson Touch Sokhak said earlier that 64 South Koreans were to be repatriated from Cambodia late Friday. After their chartered plane landed at South Korea’s Incheon International Airport on Saturday morning, the returnees were seen in handcuffs, each escorted by police officers on both sides, as they were led to a parking area where security vehicles were waiting to transport them.

Most of the repatriated South Koreans were detained in Cambodia during crackdowns on scam centers and will face police investigations at home, Seoul’s national security director Wi Sung-lac said. Authorities are likely seeking to determine whether they had willingly joined the organizations or were forced to work after being lured by false job ads.

Scam centers in Cambodia are estimated to have about 200,000 workers, including 1,000 South Koreans, according to South Korean officials.

Online scams have risen sharply since the COVID-19 pandemic and produced two sets of victims — those forced to work as scammers under the threat of violence, and the targets of their fraud via bogus investment pitches, illegal gambling schemes and even romantic ploys. Monitoring groups say online scams earn international criminal gangs billions of dollars annually.

A South Korean travel ban came into effect Thursday for parts of Cambodia, including Bokor Mountain in Kampot province, where the South Korean student was found dead. Cambodian Prime Minister Hun Manet has requested the restrictions are eased, Seoul’s Foreign Ministry said.

South Korean President Lee Jae Myung on Friday ordered authorities to take urgent action to try to remove illegal advertisements for jobs not only in Cambodia but also across Southeast Asia.

Online scam centers were previously concentrated in Southeast Asian countries including Cambodia and Myanmar, with most of the trafficked and other workers coming from Asia. But an Interpol report in June said the past three years have seen victims trafficked to Southeast Asia from distant regions including South America, Western Europe and Eastern Africa and that new centers have been reported in the Middle East, West Africa and Central America.