Myanmar’s military junta and Beijing’s embassy in Yangon said on Monday that more than 800 people suspected of cross-border fraud were arrested in a joint operation by Myanmar and Chinese police.

Scams are rampant in Myanmar, staffed by citizens from China and other countries who are often forced to work defrauding their fellow citizens in what industry analysts say is a multi-billion dollar industry.

Beijing – a key ally and arms supplier to Myanmar’s isolated junta – has repeatedly asked the military to crack down on such operations.

The Chinese embassy said on its WeChat channel that Chinese law enforcement provided information to Myanmar law enforcement, who launched raids around the city of Muse, a major trading center in northern Shan state.

Myanmar police said in a statement that they arrested 807 people “committing cross-border crimes” and seized computers, mobile phones and “fraudulent scripts.”

Among those arrested in the operation in late March were 352 Chinese citizens who were transferred to China on Sunday, the statement said.

The rest were Myanmar nationals, the statement added.

The junta issued a statement late Monday saying 352 Chinese citizens had been arrested and handed over to Chinese authorities.

Allegedly, 486 Myanmar nationals were arrested.

Last year, the U.N. human rights office said at least 120,000 people were imprisoned in Myanmar’s scam.

Many were resettled in the town of Laukai in northeastern Shan State, which was later captured by an alliance of ethnic armed groups. The alliance says it will stamp out these scams.

According to Chinese state media, more than 40,000 people suspected of being involved in online fraud were handed over to China last year in Myanmar.