Police arrested 13 members of a prostitution syndicate and detained 151 people during an anti-vice operation in Taipa, Macau, on Saturday.

Acting on a tip-off, a mainland Chinese-controlled prostitution racket that brought sex workers from mainland China, Southeast Asia and Eastern Europe into Macau was broken up after law enforcers deployed 200 officers for the operation, the Macao Daily News reported.

Police raided a spa center in Taipa and a number of locations and arrested 10 men and three women aged between 26 and 56, comprising two mainland Chinese, two Vietnamese and nine locals. There were said to be the masterminds of the syndicate.

Police also detained 151 people, including 58 sex workers and 29 customers, for further investigation. A doctor and a nurse from a clinic were taken to a police station for questioning as the syndicate organized regular medical check-ups at the clinic for the sex workers.

Officers confiscated six million Macau patacas (US$740,000) in cash, two million Macau patacas from multiple bank accounts, 4,500 condoms, a price list and documents and transaction records.

Police said the Vietnamese sex workers involved had migrant worker visas as cooks, cleaning staff or domestic workers. The group was said to have been operating since 2014, involving at least 90,000 transactions and making HK$310 million (US$40 million) in profit.