The exiled leader of china 's uighur muslim minority called on beijing to allow a UN probe to ascertain claims that muslim extremists had infiltrated into the country 's western autonomous xinjiang region.The claims came after chinese police killed 18 suspected terrorsts in an attack last week on an alleged training camp in the muslim-populated region that also left one policeman dead and another injured.just before the incident,beijing accused rebiya kadeer,the world uighur congress president living in exile in the united states,of seeking to overthrow the chinese government through terrorist activities