WHEN the authorities manage to lure or drag home a fugitive accused of corruption, they crow. But they are quieter about their equally successful campaign to repatriate Uighurs, a mostly Muslim ethnic group from Xinjiang, in China’s far west. Many Uighurs chafe at the growing presence of Han Chinese in their region, and at increasing restrictions on their personal and religious freedom. Some travel abroad, both to escape this repression and for more mundane reasons. A small number have become radicalised, and have launched terrorist attacks in Xinjiang and elsewhere. But in addition to hunting for fugitive extremists, China is also trying to prevent a big Uighur diaspora forming that could foment support for Uighurs in China, much as Tibetan exiles campaign to free their homeland.

According to human-rights groups hundreds of Uighurs have been forced back to China in the past decade from Egypt, Thailand, Vietnam and elsewhere. Far more have been detained and interrogated by Chinese agents on foreign soil. Several hundred languish in foreign jails. The actual number of returnees may be far higher, says Yun Sun of the Stimson Centre, an American think-tank. Along China’s south-western borders and across Central Asia the Chinese government often recruits locals on both sides to report the arrival of “suspicious” individuals. It frequently succeeds in getting them sent back without ever going through any official legal process.

Returnees are often sent to “re-education camps” in Xinjiang. Detention of Uighurs within China has gathered pace and up to 120,000 may be being held in such centres, according to rights groups. Uighurs in Xinjiang who maintain ties with relatives abroad are sometimes put under surveillance or even locked up.

Only a handful of those detained are violent extremists. The Chinese government says some 300 Uighurs are fighting with jihadists in Iraq and Syria. Four Chinese Uighurs with suspected links to Islamic State were convicted in Indonesia in 2015 of conspiring with Indonesian militants. More have since been arrested. Two Uighurs travelling on fake Turkish passports were among those accused of bombing a shrine in Thailand the same year.

But the charges against most Uighurs abroad are woollier. Last year Egypt’s government reportedly detained more than 200 Uighurs. Chinese security officials said they were terrorists, but many say their only crime was to study Islam. China’s government may see that as threatening enough. In Xinjiang many everyday Muslim practices have been criminalised, including wearing long beards and giving children certain religious names.

The Uighur diaspora is thought to number 1m-1.6m, the vast majority of them in Central Asia, according to the World Uyghur Congress, an activist group. That is much bigger than the Tibetan equivalent. Yet without a figurehead comparable to the Dalai Lama, a Tibetan Buddhist leader and a Nobel prizewinner, Uighurs have struggled to raise international awareness of their plight. The Chinese authorities seem determined to keep it that way, even if it means bringing them home.