A U.N. human rights panel asked China on Wednesday to disclose the fate of more than 300 Tibetan monks, whose whereabouts it said are unknown since they were allegedly arrested in April.
The U.N. Working Group on Enforced or Involuntary Disappearances said the monks were allegedly detained by Chinese security forces April 21 at the Ngaba Kirti monastery in Sichuan province, though some have reportedly since been released.
"We call on the authorities to provide full information on the fate and the whereabouts of the persons who have disappeared," the panel said.
The U.N. experts also urged authorities to investigate and punish those responsible for the alleged disappearances.
"Enforced disappearance is a terrible practice that must not be permitted to occur anywhere and no exceptional circumstances whatsoever may be invoked to justify an enforced disappearance," it said.
Chinese officials strongly rejected the allegation, denying that any monks were being held incommunicado.
"The situation mentioned (by the U.N. panel) is not true," said Xia Jinnge, of China's U.N. mission in Geneva.
The monastery has previously been the site of tensions between authorities and those advocating independence for Tibet. In March, a 21-year-old monk set himself on fire there in protest against Chinese rule.
The death of 16-year-old Rigzin Phuntsog prompted the Chinese government to enforce legal education at the monastery, including learning the basics of the Chinese constitution, criminal law and regulations on religious affairs.