China hit back on Monday at comments by Britain’s foreign secretary that accused Beijing of “gross” human rights abuses against ethnic and religious minorities in the northwest region of Xinjiang.

Rights groups and experts estimate that more than one million ethnic Uyghurs and other mostly Muslim minorities have been rounded up into a network of internment camps, which China says are facilities for job-training and to steer people away from extremism.

British Foreign Secretary Dominic Raab told the BBC on Sunday that it was “clear that there are gross, egregious human rights abuses going on… it is deeply, deeply troubling.” But foreign ministry spokesman Wang Wenbin called the comments “nothing but rumours and slander”.

“The Xinjiang issue is not about human rights, religions or ethnic groups at all, but about combating violence, terrorism and separatism,” he said Monday at a regular press briefing.

Raab said reports of forced sterilisations and mass detentions in Xinjiang required international attention, and that Britain “cannot see behaviour like that and not call it out”. But Wang said the forced-sterilisation reports were “complete nonsense”, and that the Uighur population had more than doubled in the past four decades.

Exiled Uighurs this month called for the International Criminal Court in the Hague to investigate China for genocide and crimes against humanity, filing a huge dossier accusing China of rights abuses including forcibly sterilising women. Tensions between London and China have soared over a number of topics.

Britain recently bowed to sustained pressure from Washington and ordered the phased removal of Chinese telecoms giant Huawei from its 5G network despite warnings of retaliation from Beijing. The two sides have also clashed over China’s imposition of a controversial national security law in Hong Kong — including offering a possible route to UK citizenship for some Hong Kong residents.

Britain’s Supreme Court president suggested last week that the two British judges who still serve in Hong Kong’s Court of Final Appeal — under the terms of the territory’s handover agreement with China in 1997 — could stand down unless the rule of law was guaranteed in the semi-autonomous city.

Wang said Monday that Beijing would “oppose interference in Hong Kong affairs by outside forces” and that judicial independence was “not affected” by the new security law.