International Criminal Court prosecutors have rejected calls by exiled Uighurs to investigate China for alleged genocide and crimes against humanity, the chief prosecutor's office said in a report on Monday.

The Uighurs handed a huge dossier of evidence to the court in July accusing China of locking more than one million Uighurs and other mostly Muslim minorities in re-education camps and of forcibly sterilising women.

But the office of prosecutor Fatou Bensouda said it was unable to act because the alleged acts happened on the territory of China, which is not a signatory to The Hague-based ICC.

In its annual report Bensouda's office said "this precondition for the exercise of the court's territorial jurisdiction did not appear to be met with respect to the majority of the crimes alleged."

Watchtowers on a high-security facility near what is believed to be a re-education camp where mostly Muslim ethnic minorities are detained, on the outskirts of Hotan, in China's northwestern Xinjiang region. Watchtowers on a high-security facility near what is believed to be a re-education camp where mostly Muslim ethnic minorities are detained, on the outskirts of Hotan, in China's northwestern Xinjiang region. Photo: AFP / GREG BAKER

There was also "no basis to proceed at this time" on separate claims of forced deportations of Uighurs back to China from Tajikistan and Cambodia, the ICC report said.

The Uighurs had argued that even though the alleged deportations did not happen on Chinese soil, the ICC could act because they happened on Tajik and Cambodian territory, and both of them are ICC members.

Lawyers for the Uighurs had now asked the court to reconsider "on the basis of new facts or evidence", the ICC prosecutor's report said.

China has called the accusations baseless and says the facilities in the northwestern Xinjiang region are job training centres aimed at steering people away from terrorism.

The ICC has no obligation to consider complaints filed to the prosecutor, who can decide independently what cases to submit to judges at the court, set up in 2002 to achieve justice for the world's worst crimes.