Countries must hit China with sanctions over the mass detention of ethnic Uighurs in its western Xinjiang region, hundreds of scholars said on Monday, warning that a failure to act would signal acceptance of "psychological torture of innocent civilians."

Beijing has in recent months faced an outcry from activists, academics and foreign governments over mass detentions and strict surveillance of the Muslim Uighur minority and other ethnic groups that live in Xinjiang.

In August, a United Nations human rights panel said it had received many credible reports that a million or more Uighurs and other minorities are being held in what resembles a "massive internment camp that is shrouded in secrecy" in the region.