BEIJING (Reuters) - Anti-China forces are behind criticism of policies in the far western region of Xinjiang, the Chinese foreign ministry said on Tuesday, after a U.N. panel aired accusations that a million ethnic Uighurs may be held in internment camps there.

China has said Xinjiang faces a serious threat from Islamist militants and separatists who plot attacks and stir up tension between the mostly Muslim Uighur minority who call the region home and members of the ethnic Han Chinese majority.

During the past two years, authorities have dramatically stepped up security and surveillance there, likened by critics to near martial law conditions, with police checkpoints, reeducation centers and mass DNA collection.

Members of a U.N. panel reviewing China’s rights record have said they received credible reports that 1 million ethnic Uighurs are held in what resembles a “massive internment camp that is shrouded in secrecy”.

But foreign ministry spokesman Lu Kang said the “ulterior motives” of anti-China forces were behind the “unfounded” slandering of anti-terrorism measures,

“Any defamatory rumors are futile,” Lu said in a statement, adding that the situation in Xinjiang was stable with communities of all ethnicities getting along and good momentum in economic development.

“People of all ethnic groups in Xinjiang cherish the current situation of living and working in peace and happiness.”

China has never officially confirmed the existence of detention centers in Xinjiang, but its treatment of Uighurs, as well as accounts of its use of relatives in China as leverage to silence a vocal diaspora, have spurred an international outcry.

Hu Xijin, editor of the nationalistic, state-run tabloid the Global Times, said in a tweet on Monday that “Xinjiang was once on the verge of a civil war”, but had been brought back from the edge in the past two years by government policies.

Hundreds of people have been killed in violence in Xinjiang in recent years, prompting the tough security measures by the authorities.

Rights groups and Uighur exiles say the violence stems more from Uighur frustration over Chinese controls on culture and religion, than from an organized campaign by militant groups.

China officially guarantees freedom of religion, but in recent years officials nervous about the possibility of radicalization and violence have tightened controls in heavily Muslim areas.

China’s policy of “sinification” of religion has increasingly alarmed many in other Muslim groups, who fear the government is widening strict curbs in Xinjiang to additional Muslim areas, such as the region of Ningxia and Gansu province.

As part of the campaign, the government has banned religious education for young people in mosques, ordered that the call to prayer over loudspeakers be silenced in some places, and sought to stamp out what it sees as Arab elements in mosques.