BEIJING, June 20 -- 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 China's western Xinjiang Uygur Autonomous Region and long-term peace, according to a statement from the State Internet Information Office.

The authorities will prevent terrorist materials produced overseas from being disseminated in China, clear such information online, punish website servers violating the rules and urge Internet companies to uphold their responsibilities.

"Terror video and audio products have become a major instigator of the high incidence of terrorist activities at present," the statement read.

Xinjiang saw its bloodiest day in five years on May 22 when 39 innocent people were killed in a terrorist attack in the regional capital of Urumqi.

On April 30, three people were killed and 79 injured in an attack at a railway station in Urumqi. In March, assailants killed 29 civilians and injured another 143 at a train station in the southwestern city of Kunming.

Police said most of the suspects seized in these cases were led on by terrorist video and audio products to carry out terrorist activities.

Many of them had learned how to make explosives through online tutorials. They exchanged experiences of making explosives and propagating Jihad through chat tools, text messages and illegal preaching sites.

The office described this year's situation as "especially grave" because the amount of terrorist video and audio material released by separatist forces including the East Turkistan Islamic Movement has shot up.

"These materials, which propagate Jihad, terrorism and religious extremism, have been spread incessantly in China," according to the statement. "They have had a strong instigation effect and are extremely harmful."

The office encouraged the public to provide it with tip-offs and promised rewards of up to 100,000 yuan (16,055 U.S. dollars) for those who offer important clues.