A car bomb targeted a crowd at Tian'anmen Square in Beijing on Oct 28, 2013. [Photo Provided to China Daily]

Measures taken

Internet and technology companies are taking action.

The companies have instructed their employees of the danger these videos pose and hold meetings every week to make their campaign against them more effective.

The campaign not only targets websites as the enterprises also delete harmful information on their Twitter-like platforms and instant messaging tools, such as Weibo and WeChat.

Zhao Tian, an employee responsible for tackling terror videos at Sina, one of China's largest Internet giants, said the company had established a specialist group to deal with online terror-related information on March 1, the day terrorists killed 29 civilians and injured another 143 at a railway station in Kunming, Yunnan province.

The group has deleted postings involving religious extremists and more than 800 messages relating to guns and violence, Zhao added.

A representative in charge of the video program from Tencent, another large Chinese technology company, echoed Zhao's view, saying her company has added more than 600 employees to boost online security.

"We found people with a better knowledge of the Uygur language and better able to monitor materials uploaded on our websites," the representative said, adding they were also enforcing technical barriers.

But Zhao Danyang, content manager of Youku, China's largest video website, said that his group, about 300 people, still needed authorities to help identify whether a video actually involves terrorists as some may seem, at first glance, to be innocent.

"Some content can be confusing, insofar as it may not actually be apparent if there is a hidden message, so we have to hand it to the Ministry of Public Security," he added.

The anti-terror expert Li Wei agreed, suggesting that the government publish specific definitions of what constitutes terror information and provide more background knowledge and expertise for companies through training.

The more details and requirements we have, the more accurate and effective we will be in tackling terror-related information, he added.