Sri Lanka Police on Thursday urged residents to immediately notify the nearest police station if groups of Chinese, Vietnamese or Myanmar nationals are found living suspiciously in apartments, houses or hotels, Newswire reported.

The advisory follows a string of large-scale raids over the past week that uncovered foreign-led cybercrime operations across Colombo and its suburbs.

On May 7, the Mount Lavinia Division Criminal Investigation Unit, acting on a tip-off, arrested 30 foreign nationals at a rented house in Boralesgamuwa. Officers seized five computers, 26 mobile phones and five Wi-Fi routers. Of the suspects, 21 were Chinese — including three women — and nine were Vietnamese. Investigators have linked the group to a larger network of 150 nationals arrested by the CID on April 2.

A day earlier, Colpetty Police arrested 74 foreign nationals at Kollupitiya over alleged cybercrimes and visa breaches.

On May 2, Walana Central Anti-Corruption Strike Unit officers and Thalangama Police arrested 36 Chinese men and one woman in Thalangama under the Computer Crimes Act, with suspects ranging in age from 23 to 44. The same day, Welikada Police raided a housing complex on Rajagiriya Welikada Road and arrested 120 foreign nationals from Myanmar, Vietnam, the Philippines, the Maldives, Romania and Thailand.

Police said information leading to the recent operations was provided by the Senior Superintendent of Police, Nugegoda, and the Director of the Environmental Protection Division. Suspects are being produced before courts as the Criminal Investigation Department and its Computer Crimes Investigation Division continue investigations.

The public-reporting appeal is a new front in the operation, building on an earlier directive for Bandaranaike International Airport to apply special checks on arrivals from countries linked to recent cybercrime cases.