Hong Kong (CNN) British diplomats who visited Xinjiang, in China's remote northwest, have confirmed reports that large numbers of Muslims are being held in so-called "vocational education centers."

UK Foreign Secretary Jeremy Hunt told Parliament earlier this week that London had viewed the reports which began emerging in recent months "with a lot of concern."

"We had our own diplomats visiting the Xinjiang province in August and they concur that those reports (of internment camps) are broadly accurate," he said.

Last month, China launched a fierce defense of its policies in the isolated region , where the predominantly Muslim Uyghur ethnic group make up a large minority.

At a regular press conference Thursday, Chinese Foreign Ministry spokesman Lu Kang said Beijing was "firmly opposed to the UK's use of the so-called Xinjiang issue for any political purpose."

"China's anti-terrorist and anti-extremist measures are aimed at preventing and stopping violent terrorist attacks," Lu said.

'Safe and stable'

International outrage has been growing over reports the Chinese government has transferred as many as one million people into "re-education camps," where former detainees say they were forced to endure intensive "brainwashing" sessions, including close study of Communist Party propaganda.

These reports were initially denied by Beijing, but in recent weeks the government has launched a vocal defense of the policy as necessary for national security and ethnic harmony.

"Today's Xinjiang is not only beautiful but also safe and stable. No matter where they are or at what time of the day, people are no longer afraid of going out, shopping, dining and traveling," Shohrat Zakir, a high-ranking Xinjiang government official, told state-run news agency Xinhua in October.

"There is still a long way to go for southern Xinjiang to eradicate the environment and soil of terrorism and religious extremism."

Xinjiang quietly legalized "vocational skill education training centers" on October 10, which the law said would be used to "carry out anti-extremist ideological education."

That move came less than two months after a Chinese government spokesman completely denied the existence of re-education camps during a UN hearing on human rights.

While Xinjiang has a long history of oppression -- driven by Beijing's paranoia of Uyghur nationalism and separatism -- the most recent crackdown is largely unprecedented.

In an August 29 report, the UN Committee on the Elimination of Racial Discrimination expressed alarm at reports of Uyghurs and other Muslims being held for long periods of time without charge or trial "under the pretext of countering terrorism and religious extremism."

A UN committee will issue another report next week on the situation in Xinjiang, and Uyghur have promised to hold mass protests in Geneva calling for a reversal in China's policies.

Hunt was asked by British lawmakers during a regular question session in Parliament, and did not go into detail about what UK diplomats had seen during their trip to Xinjiang.

"I think this issue is of very great, and growing, concern," he said, adding that he had raised it with Chinese Foreign Minister Wang Yi during a recent trip to Beijing, and would continue to bring it up "in all appropriate forums."