COLOMBO - Sri Lankan authorities arrested 30 Chinese and Vietnamese nationals Thursday in the latest crackdown on cyberscams, raising the total number detained since last weekend to 261, police said.

The latest arrests were made in Werahera, a suburb of the capital. Police added that 74 Vietnamese nationals arrested elsewhere in the capital Wednesday were remanded until May 14.

Crime groups worldwide are conducting online scams that defraud victims of tens of billions of dollars annually, often through cryptocurrency fraud and fake romantic relationships.

In Sri Lanka, authorities cracked down on two suspected cyberscam centres on May 3, arresting 157 people. "They had entered the country on tourist visas and were illegally employed, while some had overstayed their visas," police spokesman Frederick Wootler said.

A Colombo magistrate ordered a forensic examination of computers and mobile phones seized from the alleged scam centre in the Kollupitiya area, where the 74 Vietnamese were arrested Wednesday. The suspects are aged 19 to 39.

This follows the arrest of 152 foreign nationals, mostly Chinese, a month ago for allegedly running a cyberscam from a hotel in the northwest. Immigration authorities also arrested 135 Chinese nationals in March for similar operations, who have since been deported.