Police on the Chinese mainland and Taiwan worked together to crack a cross-Strait drug-trafficking ring, a spokeswoman for Chinese mainland authorities said Wednesday.

Police in Guangdong, Fujian and Taiwan had arrested five people on Monday evening, after a three-month joint investigation, Fan Liqing, a spokeswoman for the Taiwan Affairs Office of the State Council, told a regular press conference in Beijing Wednesday.

Police also seized 154 kilograms of Ketamine and 3 kilograms of methamphetamine (also known as "ice"), Fan said.

Fan gave no other details on the police cooperation nor the criminal activities, but she said the case had effectively halted the operations of a long-term cross-Strait drug trafficking group.