An Fengshan, spokesperson for the Taiwan Affairs Office of the State Council. (File Photo: Xinhua)

A Chinese mainland spokesperson on Sunday urged Taiwan to immediately stop infiltration and sabotage activities against the mainland.

According to the relevant investigation, Taiwan's intelligence agencies have significantly increased their steal of intelligence, infiltration and sabotage activities targeting the mainland for a certain period of time, said An Fengshan, spokesperson for the Taiwan Affairs Office of the State Council.

The mainland's security organs have launched a special campaign to crack down on these activities by Taiwan, An said.

"Taiwan authorities must avoid any further damage to the increasingly complicated and intense cross-Strait relations," he added. (with input from Xinhua)