China's government has tightened control over popular instant messaging services after reportedly telling a South Korea official that access to some foreign services was blocked because they were used to exchange terrorism-related information.

The government announced that only established media companies will be allowed to release political and social news.

Accounts that have not been approved by the instant messaging service provider are forbidden to publish or reprint political news, the official Xinhua news agency said.



It added that service providers must verify and publicly mark accounts that can publish or reprint political news.

That would curtail the growing use of instant messaging services by journalists and scholars to distribute

independent news reports and commentary.

The ruling Communist Party has repeatedly tightened controls over microblogs and other social media that give Chinese a platform to express themselves to a large audience, the AP news agency reported.

China informed South Korea it had blocked access to two mobile messaging services, Kakao Talk and Line, which it said were used to exchange terrorism-related information, according to a South Korean official who asked not to be named because he was not authorised to speak on the matter.

'Infiltration of hostile forces'

China's government is on edge about security following a series of deadly attacks that authorities blame on Uighurs seeking independence for the country's northwestern region of Xinjiang.

Beijing says it has confirmed terrorism-related information circulated through Kakao Talk and Line, the South Korean official said.

In May, the government launched a one-month crackdown on instant messaging services to stop what it called the "infiltration of hostile forces."

Authorities said it targeted people spreading rumours and information about violence, terrorism or pornography.

The campaign focused on public accounts on services including WeChat in China, a mobile message service run by Tencent, which has surged in popularity in the last two years.

Tencent said it would work within the new regulations which it stressed would only apply to public accounts and not to

everyday users, the Reuters news agency reported.

Microblogging targeted

Last summer, Beijing cracked down on microblogging services such as Sina Weibo.

Authorities closed accounts of some microbloggers and detained bloggers on criminal charges of spreading rumours or other offences.

The crackdown helped drive users to WeChat, which allows individuals to set up public accounts that others can subscribe to, similar to the microblogging feature of having followers but without a word limit.

Journalists and scholars have since set up accounts and attracted sizeable followings on WeChat.

The rules "could cool down the traffic of WeChat public accounts and discourage journalists from setting up individual

WeChat public accounts," said Fu King-wa, an assistant professor at the University of Hong Kong's Journalism and Media Studies Centre.