The United States said on Friday it had removed from its list of terror groups a shadowy faction regularly blamed by China to justify its harsh crackdown in the Muslim-majority Xinjiang region.

In a notice in the Federal Register, which publishes new US laws and rules, Secretary of State Mike Pompeo said he was revoking the designation of the East Turkestan Islamic Movement (ETIM) as a “terrorist organisation”.

“ETIM was removed from the list because, for more than a decade, there has been no credible evidence that ETIM continues to exist,” a State Department spokesperson said.

The administration of George W. Bush in 2004 added ETIM, also sometimes called the Turkestan Islamic Party, to a blacklist as it found common cause with China in the US-led “war on terror”. Beijing has regularly blamed ETIM for attacks as it justifies its measures in Xinjiang, where rights groups say that one million or more Uighurs or other Turkic-speaking, mostly Muslim people are incarcerated in camps.

But scholars say that China has produced little evidence that ETIM is an organised group or that it is to blame for attacks in Xinjiang, which separatists call East Turkestan.

The Washington-based Uighur Human Rights Project called the State Department decision “long overdue” and a “definitive rejection of China's claims”.

“The harmful effects of China's exploitation of the imagined 'ETIM' threat are real — 20 years of state terror directed at Uighurs,” said the group's executive director, Omer Kanat.

But China's foreign ministry spokesman on Friday expressed China's “strong dissatisfaction and firm opposition to the US decision”, urging the US to “stop backpedaling on international counter-terrorism cooperation”.

China has acknowledged camps in Xinjiang but describes them as vocational centres meant to reduce the allure of Islamic radicalism.

While experts have doubted a role of ETIM, China has suffered a series of attacks that authorities blamed on Uighur separatists.

In 2014, assailants stabbed to death 31 passengers at a railway station in the southwestern city of Kunming.

In 2009, hundreds died in Xinjiang's capital Urumqi in riots that largely targeted China's majority Han.

Activists allege that China is trying to forcibly integrate Uighurs by indoctrinating them with communist ideology and making them renounce Islamic customs, a claim Beijing denies.

Pompeo has previously called the mass incarceration “the stain of the century” and US senators across party lines are seeking to declare China's treatment of the Uighurs genocide.

ETIM was listed on the US Terrorism Exclusion List, which affects entry of people into the country, but was never hit with the tougher designation of Foreign Terrorist Organisation.