A Chinese government-backed agency has said Facebook and YouTube have refused to delete material involving terrorism and violence, which have become a major challenge, especially in the Xinjiang Uygur autonomous region.

In a campaign aimed at cracking down on online content with porn, scams, terrorism and violence, the China Internet Illegal Information Reporting Center received complaints about videos that promote jihad from the East Turkestan Islamic Movement - part of an international terrorism network listed by the United Nations Security Council - in the world's largest tech and social media websites including Facebook and YouTube.

Facebook and YouTube have made little effort to delete such information and hardly any content has been removed since its report of these gruesome videos, said the organization under the Internet Society of China.