Terrorist groups are using the Internet to recruit people, raise funds and plan attacks in China, the State Internet Information Office (SIIO) said on Tuesday.

Calling audio and video materials that promote terrorism a "cancer" of the Internet, SIIO spokesman Jiang Jun told reporters at a press conference that terrorist forces have "turned the Internet into a principal tool for their operations."

He said the groups have sought to "spread terrorism and violent beliefs and teach terrorist skills online," adding that such actions must be struck down decisively.

China launched a campaign on Friday to rid the Internet of audio and video materials that promote terrorism and violence.

The move is aimed at safeguarding social stability in northwest China's Xinjiang Uygur Autonomous Region and long-term peace, according to the SIIO.