So-called Philippine offshore gaming operators, or POGOs, are the country’s fastest-growing industry. They have caused friction because of allegations of widespread tax evasion and the influx of tens of thousands of immigrant workers.

A total of 342 Chinese without working visas were arrested on Thursday in a raid of a Manila-based POGO outfit operating without a permit from the gaming regulator, according to the immigration service.

“We had reason to suspect that the company is a front for illegal cyber activities and investment scams,” Fortunato Manahan, intelligence chief of the immigration service, said in a statement.

“We coordinated this operation with the Chinese government, which confirmed the company’s involvement in illegal activities, victimising mostly their compatriots in China,” he said without giving details, adding the illegal workers will be deported.

Since President Rodrigo Duterte was elected in 2016 and decided to pursue closer trade and investment ties with China, Manila has seen a huge influx of mainlanders to work in the country’s online casino boom, which targets Chinese gamblers.

Some Filipinos grumble that POGOS are driving up property rates while not providing job opportunities because not enough locals speak Chinese languages.