Photo/IllutrationA view of Kuala Lumpur (Asahi Shimbun file photo)

KUALA LUMPUR--Malaysian authorities have arrested 680 Chinese nationals suspected of operating an extensive online fraud operation cheating people in their homeland, officials said on Thursday.

A team of 150 Immigration Department officers raided the suspects' well-guarded headquarters in the town of Cyberjaya on Wednesday, the director general of the Immigration Department, Khairul Dzaimee Daud, said in a statement.

About 100 suspects managed to escape, and some were hurt in the melee, Khairul said. The gang was believed to have operated from the premises for about six months.

"The modus operandi of this syndicate is to target victims in China," he said.

"They are offered high and quick profits. The operators send a code to customers of a Mandarin-language website. All transactions were done through WeChat Pay or banks in China."

The Immigration Department said this was believed to have been the largest ever online scam by Chinese nationals in Malaysia.