China has dealt another blow to the country’s ‘shadow banking’ industry by taking down an operation linked to illegal gambling.

On Wednesday, China’s official Xinhua news agency reported that authorities had arrested 14 individuals tied to four gangs in the city of Dalian in northeastern Liaoning province. The gangs reportedly offered gambling services in Macau and South Korea, while using the Agricultural Bank of China to process their transactions.

The gangs collectively held over 2k accounts at the AgBank, China’s third largest bank in terms of assets. Each gang reportedly conducted illegal transactions worth over $100k per day, with the total volume of illegal transfers exceeding over $4.5b during an unspecified time period.

The arrests mark the latest result of Beijing’s desire to stamp out movement of ‘gray capital’ derived from illicit activities. Last week, the Ministry of Public Security announced the takedown of an illegal banking network that handled over $64b in unauthorized transactions, a good portion of which involved illegal gambling.