A UN human rights committee has heard there are credible reports that China is holding a million Uighurs in "counter-extremism centres".

Gay McDougall, a member of the UN Committee on the Elimination of Racial Discrimination, raised the claims at a two-day UN meeting on China.

She said she was concerned by reports that Beijing had "turned the Uighur autonomous region into something that resembles a massive internment camp".

Its 50-strong delegation said it would address questions on Monday, when the session in Geneva continues.

The Uighurs are a Muslim ethnic minority mostly based in China's Xinjiang province. They make up around 45% of the population there.

Xinjiang is officially designated as an autonomous region within China, like Tibet to its south.

Reports that more and more Uighurs and other Muslim minorities are being detained in Xinjiang have been circulating for some months.

Human rights groups including Amnesty International and Human Rights Watch have submitted reports to the UN committee documenting claims of mass imprisonment, in camps where inmates are forced to swear loyalty to China's President Xi Jinping.

The World Uyghur Congress said in its report that detainees are held indefinitely without charge, and forced to shout Communist Party slogans.

It said they are poorly fed, and reports of torture are widespread.

Most inmates have never been charged with a crime, it is claimed, and do not receive legal representation.

China is said to carry out the detentions under the guise of combating religious extremism.