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

Targeting videos

The presence of these terror videos is increasing on some Chinese websites, the SIIO said.

The SIIO launched a campaign to tackle the spread of these videos on June 20, and posted a documentary highlighting the harm they can cause to people who watch them.

More than 30 Web companies signed an agreement on that day to monitor and get rid of such videos within one month and root out related online content in six months.

The Internet enterprises were asked to establish an online center where people with suspicions can contact public security departments.

State-owned telecom giants should also play a key role in preventing the videos from spreading on mobile phones, especially second-hand ones, the SIIO spokesman said.

China has also been strengthening online security since last year and in December the government issued guidelines on combating terror-related videos and audios, while in March such materials were banned in Xinjiang.

Li Wei, the anti-terror expert, praised the campaign, but also stressed the importance of broader global cooperation.

"Cross-border broadcasting and overseas production bases are challenges we face," Li said.

Although the UN has requested that countries improve supervision and crack down on terror, greater cooperation is needed, he said.

Currently video producers make use of the Internet to spread their ideology, but they could cause greater damage if they carried out online terror attacks, he added.