LATEST: China has threatened to blacklist foreign artists who speak out in favour of Tibetan freedom, following pop star Bjork's recent onstage chant for the mandated country. The communist country, which has ruled Tibet since 1951, has pledged to impose more rigid restrictions on performers after the Icelandic singer yelled "Tibet" several times during her song Declare Independence at a concert in Shanghai on Sunday (02Mar08). In a statement on its website, the Ministry of Culture states: "We will further tighten controls on foreign artists performing in China in order to prevent similar cases from happening in the future. "We shall never tolerate any attempt to separate Tibet from China and will no longer welcome any artists who deliberately do this. "Some artist deliberately turned a commercial show into a political performance, which not only broke Chinese law, but also hurt Chinese audiences' feelings." It is not the first time Bjork has expressed support for Tibetan independence - she performed at a Free Tibet concert in San Francisco, California in 1996.