All acts of terror are shocking, but those involving knives – the most intimate of murder weapons – carry a particular horror. Saturday's murders in Kunming station of 29 people, and the wounding of 129 more, by 10 masked, black-clad men and women, add a dimension of scale to an already gruesome act. The victims were mostly ordinary travellers in one of China's most peaceful and multi-ethnic provincial capitals. The perpetrators, according to official Chinese statements, were from Xinjiang, the mineral-rich and predominantly Muslim north-west region. If this is the case, this incident will have profound repercussions in China.

Disaffection with Chinese rule is not new in Xinjiang: it was the site of several rebellions in the 19th and 20th centuries. An independent state of East Turkestan was declared in 1933, existing briefly before being absorbed into the People's Republic of China and designated the Xinjiang-Uighur autonomous region, following the Communist victory in 1949.

The most recent outbreak of serious violence in Xinjiang goes back to 2009, when an ugly inter-ethnic episode in China's industrialised south-east triggered a violent and sustained reaction in Xinjiang, provoking more repression, in turn, on the part of the state.

Without evidence, we can only speculate what cause those 10 masked men and women hoped to advance by the Kunming massacre. The government routinely attributes such violent acts to separatists and religious extremists, conflating a variety of unconnected grievances and allegiances into one.

Many Xinjiang Uighurs are indeed disaffected: their complaints range from the routine, daily discrimination, to resentment of the state's tight control of their culture and religion. Others react against the increasing pressure of Chinese migration. State-directed colonisation into Xinjiang began in the 1950s, and migration into the province has accelerated since China opened its western borders and ramped up investment in infrastructure. Development has made Xinjiang richer, but the beneficiaries have been Han Chinese, disproportionately, rather than the Xinjiang's Uighurs, Kazaks or Kirgiz. Some certainly want to claim independence, as their neighbours in the former Soviet Central Asia were able to do after the collapse of the USSR. But this combination of grievances does not equate to a general desire to establish an Islamic state on the model of the Taliban's Afghanistan, nor does it support the Chinese government's case that all Xinjiang's woes can be blamed on the external influence of global jihad.

Since 9/11, China has been eager to align any trouble in Xinjiang with international terrorist movements. While there is evidence of sporadic contact between Xinjiang groups and militants in Central Asia and Afghanistan, Xinjiang's militants have largely been isolated from external support by China's close security alliances with its Central Asian neighbours, and with Pakistan.

In 2002, the US state department, designated a Uighur group, the East Turkestan Islamic Movement (Etim), as a terrorist organisation, but later removed it from the list. Beijing has claimed that Osama bin Laden trained and supported Chinese Muslim radicals, but the 22 Uighurs who were captured in Afghanistan after 9/11 and detained in Guantánamo Bay have all been released and exonerated.

Given its oppressive treatment of Muslims in Xinjiang, it is perhaps more surprising that China has not figured as a prime target of jihadi propaganda, let alone action, a pass it obtains largely through its strategic alliance with Pakistan.

In return for Chinese support against India, Pakistan's intelligence services have been careful to ensure that their own sponsored militants turn a blind eye to China's repression of their fellow Muslims. Saturday's events, horrific though they were, do not necessarily prove a link to external jihad, but bringing violence on this scale to the majority population will have profound consequences in China. The leadership was rattled last October when, shortly before an important Communist Party plenum, a Uighur named Usmen Hasan crashed a car carrying himself, his wife and his mother in Beijing's Tiananmen Square, killing two tourists and the car's three occupants. Chinese security services blamed Etim, although the incident remains obscure.

The Kunming attacks represent a major escalation of violence against Han Chinese outside Xinjiang, and, no doubt, a bid for global as well as national attention.

The Chinese authorities are well aware that this attack comes on the eve of an important political moment – the joint annual meetings of National People's Congress and the Chinese People's Political Consultative Conference . The government has promised to "strike hard" against terrorism. Uighurs, already the objects of deep suspicion by both the state and the Han majority, will pay a heavy price.