Twenty suspects have been detained for alleged running an underground soccer gambling business in Guiyang, capital of Guizhou province, police announced on Monday.

Police said some of the suspects are ex-convicts and drug addicts. The gang was taking bets on overseas gambling websites and became extremely active recently due to the ongoing FIFA World Cup.

Police also said more than 80 million yuan ($12.88 million) was used during the gambling process.

Fourteen vehicles and 20 computers that were used for taking bets were seized, and bank accounts with more than 2.88 million yuan of suspected gambled funds were frozen.

The agencies will continue the high-profile crackdowns to fight against soccer gambling, police said.