Yesterday's UN Human Rights Day was marked by the starkly different fates of China's two Nobel laureates. While Nobel literature laureate Mo Yan hogged the limelight at the awards ceremony in Stockholm yesterday, 2010 Nobel Peace Prize winner Liu Xiaobo remains behind bars, convicted on subversion charges and serving an 11-year sentence at a prison more than 400 kilometres northeast of Beijing. Apart from celebrating the 64th anniversary of the UN General Assembly's adoption of the Universal Declaration of Human Rights, December 10 also marked the day that Charter 08 - a manifesto Liu helped draft calling for sweeping political and legal reforms - was published four years ago. Liu, who turns 57 later this month, was detained in 2008 and was convicted in December 2009 of inciting subversion for co-drafting the human rights petition. While Mo has declined to join 134 Nobel laureates from across the world in an appeal for Liu's release, mainland rights activists proposed a series of activities to mark the date and to continue calling on Beijing to release Liu and his wife, Liu Xia , who has been kept under house arrest, largely incommunicado. Meanwhile, jittery authorities tightened security near the homes of the jailed Nobel laureate and other dissidents, according to several activists, including Hu Jia , who was himself jailed for more than three years on subversion charges. Hu told Agence France-Presse that he was barred from leaving his home after he proposed organising events near Liu's home. Hu made a Twitter post on Friday suggesting that a park near Liu Xia's home, in the capital's western suburbs, would "be a good place to hold a human rights press conference" to mark the date. "The police are keeping me in my home until Tuesday to prevent me from meeting people like you so that I will not be photographed or filmed for Human Rights Day," he said. Hu, one of the mainland's most high-profile dissidents, who has remained under close surveillance after his release last year, could not be reached later yesterday. According to Twitter messages by Hu and other activists, many mainland rights campaigners flocked to Liu's home on Saturday, the date that Liu Xiaobo was detained four years ago, to show their support for his wife, who has been under house arrest and surveillance since the award was announced. But they failed to meet her due to heavy police presence. One of the signatories of Charter 08, Xu Yishun , from Baoding , Hebei , was among those taken away by police, along with two of his family members, according to a US-based rights website. They were detained for at least seven hours and released early yesterday. In Hong Kong, about a dozen activists took to the streets yesterday and sent about 1,000 Christmas cards to the jailed Nobel laureate and his wife to mark Human Rights Day. Although hailed as a national hero since the prize announcement in October, Mo, the vice-chairman of the government-backed China Writers' Association, has been widely criticised as being a Beijing stooge for his refusal to speak up for Liu. Echoing the awards ceremony in Oslo two years ago, when Liu was represented by an empty chair, a mainland artist reportedly sent another chair to the Nobel committee, according to journalist-artist Wu Hongfei .