Police detained 166 Chinese nationals and one Vietnamese national yesterday morning in Cambodia’s biggest police operation ever conducted in cooperation with a foreign government.

With assistance from the Chinese government, the suspects were arrested on suspicion of international telecommunications fraud, National Police spokesman Kirt Chantharith said.

“This is the first large-scale operation to crack down on cross-border crimes in which we have cooperated with international police [to arrest] suspects of internationally networked organisations,” he said.

The search continues for additional suspects who escaped during operations yesterday in Phnom Penh, he added.

Police in Taiwan, Indonesia, Thailand and Malaysia arrested 313 Chinese citizens yesterday in similar joint operations, Kirt Chantharith said.

Chinese Embassy officials were still gathering information on the raids yesterday afternoon. An embassy spokesman confirmed that the Chinese government had worked together with local police in apprehending the suspects, though he could not confirm the nature of the allegations against them.

A furniture merchant on Street 21 in the capital’s Chamkarmon district said she had witnessed a large-scale arrest yesterday morning. Police apprehended several Chinese nationals at a large villa next to her furniture shop, she said.

Residents of Sihanoukville also reported raids. A local business owner, who asked not to be named, said police vehicles holding handcuffed detainees could be seen yesterday on city streets. It was rumored that the suspects were Chinese and Taiwanese, he said.

“The police were in and out of hotels – armed police. They were obviously looking for someone,” he said.

“You could ask any local and they would be able to tell you the same. It was very obvious something was going on.”

The Interior Ministry’s immigration department is holding the suspects for questioning before they are repatriated to China, Kirt Chantharith said.

“In principle, we will repatriate them back to face trial under Chinese law, but we don’t know when we will do that because the investigation is still ongoing,” he said. Kirt Chantharith said the fraud was related to a telecommunications scam but was unable to provide details.

“I am not able to explain how the suspects used the network to extort money overseas. They processed it through a system known as OIC,” he said.

OICs, or “offer-in-compromise” scams, swindle people who owe taxes into paying for services that claim to reduce their total debt, according to financial information site bankrate.com.