Clare Nuttall in Astana -

Thousands of kilometres from China's booming east coast, the Xinjiang region has become Beijing's gateway to Central Asia. But as the former backwater's economy grows, rising social tensions have erupted repeatedly into deadly violence, most recently in June. Should the situation in this ethnically divided region worsen, it could have negative consequences - both political and economic - for Central Asia.

Sharing borders with Kazakhstan, Kyrgyzstan and Tajikistan, the Xinjiang Uyghur Autonomous Region is the point of entry for China's trade with the resource-rich region. Back in the early 1990s, this was mainly small-scale trade in consumer goods; Xinjiang's capital Urumqi and the former silk road city of Kashgar are both within a 1,200km radius of Almaty and Bishkek, where two of Central Asia's main wholesale bazaars are located.

Two decades later, not only has trade grown 100 times, increasing from $460m in 1992 to almost $46bn in 2012, it also flows in the opposite direction with oil, gas and minerals entering China via Xinjiang. China is now the largest trading partner for both Kazakhstan and Turkmenistan, and among the top three partners of Kyrgyzstan, Tajikistan and Uzbekistan, China's Deputy Commerce Minister Jiang Yaoping announced on May 28, Kazinform reported. As of 2010, while Central Asia accounted for just 1% of Chinese exports, the region absorbed no less than 83% of the Xinjiang region's exports, with 52% going to Kazakhstan.

Kazakhstan's trade with China saw a steady increase during Karim Massimov's term as prime minister from 2007 to 2012. An ethnic Uighur educated in China, Massimov is widely credited with further opening up trade with China.

With China's growing demand for raw materials, there have been heavy investments into infrastructure to export Central Asian oil, gas and minerals. The Central Asia-China gas pipeline exports gas from the Turkmen Caspian basin to Xinjiang, via Uzbekistan and Kazakhstan, with Uzbekistan starting exports through the pipeline in mid-2012. Kazakhstan also has a direct oil pipeline link to China, and exports are expected to increase after the launch of production at the offshore Kashagan oilfield, where China National Petroleum Corp (CNPC) will soon become a shareholder. There are also plans to build new road and rail infrastructure connecting Central Asia and Xinjiang.

Minority report

However, Xinjiang has become increasingly restive in the last two decades as millions of Han Chinese settled in the region, turning the Uighurs, who now make up just 48% of the population, into a minority. Growing social inequality is another factor. This has raised concerns in the Chinese government both about internal security and the possible consequences for trade with Central Asia.

The most serious outbreak of violence was in 2009, when at least 200 people were killed in days of rioting in Urumqi. The trigger was a demonstration over the "Shaoguan incident", the deaths of two Uighurs in a fight in China's Guangdong province, but it escalated into attacks on local Han Chinese and large-scale inter-ethnic fighting.

The violence also had an impact on Kazakhstan and other Central Asian countries, which temporarily banned travel to Xinjiang. The move was intended to protect their own citizens and seal the borders against any potential spillover effects, but caused a temporary slump in trade.

Violence broke out again in June, leaving at least 35 people dead, with unofficial sources saying the death toll was considerably higher. The first incident was in the Turpan region, where a group armed with knives launched an early morning attack on a police station and local government offices, torching police cars and killing nine police officers and eight civilians before security forces opened fire. Just days later, there was a second outbreak of violence in Hotan, in the south of the region.

The Chinese press quotes foreign ministry spokesman, Hua Chunying, describing the Turpan riot as a "violent terrorist attack", the usual line taken on incidents in the region. However, there appears to be some acknowledgement of the social and economic pressures behind the attacks.

"The economic modernisation programme in Xinjiang has had less benefit for the ethnic minorities, especially the Uighurs, resulting in economic stratification between rural and urban areas, and different ethnic groups," says Dr Michael Clarke, research fellow at Griffith University and author of "Xinjiang and China's Rise in Central Asia". "Both Turpan and Hotan have experienced rapid urbanisation in the last 10 to 15 years, so there is a direct correlation between the central government's modernisation programme in Xinjiang and growing ethnic resentment."

Heading off trouble

Ironically, since the breakup of the Soviet Union the Chinese government had been pushing to develop Xinjiang, and promote trade with Central Asia, in an attempt to ensure the region's future stability. This includes safeguarding China against any spillover of instability from Central Asia or Afghanistan, says a report from the International Crisis Group.

"China's strategy seems to be the creation of close ties with Central Asia to reinforce economic development and stability, which it believes will insulate itself, including its Xinjiang Uighur Autonomous Region, as well as its neighbours from any negative consequences of NATO's 2014 withdrawal from Afghanistan," writes the Crisis Group's Central Asia project director, Deirdre Tynan.

Despite being divided by the Chinese and Russian spheres of influence, Central Asia and Xinjiang share a common history and religion, and the Uighur language is similar to the Turkic Central Asian languages. There is a substantial Uighur minority in Kazakhstan of up to 200,000 people, while Kazakhs are the second-largest national minority in Xinjiang.

During the Soviet era, Uighurs in the Soviet Union were allowed a higher degree of cultural expression, probably in an attempt to unnerve the Chinese authorities. This continued immediately after independence, with a conference on the creation of an independent "Uighuristan" held in the former Kazakhstani capital Almaty in 1992.

This raised alarms in Beijing that the newly independent Central Asian states - especially Kazakhstan - could inspire the Uighur minority to push for independence. However, with the two revolutions in Kyrgyzstan and Kazakhstan's own 2011 Zhanaozen tragedy, internal security has been made a higher priority in Central Asia.

While there has not yet been any political fallout in Central Asia from the 2009 and 2013 violence in Xinjiang, there are concerns on both sides of the border about the spread of unrest in either direction. "The potential for spillover is always there, given Kazakhstan's large Uighur population and the number of Uighur political organisations active in Kazakhstan. However, in terms of the recent violence, spillover to Kazakhstan in particular seems unlikely, give the security cooperation developed between the Kazakh and Chinese authorities," says Clarke, citing the Shanghai Cooperation Organisation (SCO) as an example.