South Korea has tightened monitoring of popular social networking sites to curb illicit content including an upsurge in North Korean propaganda, officials said Thursday. The Korea Communications Standards Commission said an eight-member team was launched on Wednesday to examine Facebook and Twitter posts and smartphone applications. Users will be asked to delete "harmful or illegal" content relating to pornography, gambling, drug abuse, false information, and defamation which are all criminal offenses in South Korea, it said. "Postings and sites that praise North Korea or glorify its leaders are also the target of our work as they increased rapidly this year," team leader Han Myeong-Ho told AFP. "North Korea has stepped up its propaganda drive through social networking sites," he added. If the users refuse to take down the material, the commission will order internet service providers (ISPs) to block access to offending accounts and sites, Han told AFP. Criminal charges could be laid in serious cases, he said, but added that "most individuals and site operators voluntarily take out postings when they are asked by authorities to do so." The South's clampdown has triggered an outcry from liberal groups which have accused the government of trying to gag the private exchange of opinion through social networking sites. "The commission must immediately stop its anachronistic act restricting freedom of expression," six civic groups said in a joint statement on Tuesday. Critics say the Seoul government is seeking to muzzle its opponents through the guise of fighting North Korea's propaganda campaign. North Korea last year joined Twitter under the name @uriminzok ("our own nationals"), and made its foray onto the popular video-sharing site YouTube. The communist country has attracted more than 10,000 followers on Twitter. And last month the North's main government website (www.uriminzokkiri.com) began adding icons for users to post stinging postings attacking Seoul and Washington on social networks. South Korea blocks pro-North Korean sites and access to the North's websites under a tough security law but some people in the South use proxy servers to access them. The North's publicity drive has prompted South Korean security authorities to step up a crackdown on pro-North activities in cyberspace. On November 11, a former army officer was arrested for operating an online community to disseminate propaganda postings obtained from North Korean websites. Freedom House, a Washington-based NGO, downgraded South Korea's media status from "free" to "partly free" this year. The move reflects an increase in official censorship, particularly of online content, and "the government's attempt to influence media outlets' news and information", it said. The Seoul government denies it has ever attempted to influence news media.