Beijing: Attackers killed at least 31 people Thursday when they ploughed two vehicles into a market and threw explosives in the capital of China's Xinjiang region, in what authorities called the latest "severe terrorist incident" to hit Uighur homeland.
More than 90 people were also wounded when two off-road vehicles drove into a crowd in Urumqi, with one of them exploding, the regional government's Tianshan web portal said, in an attack with echoes of a fiery car crash in Tiananmen Square last year.
China has seen a series of incidents in recent months targeting civilians, sometimes far from Xinjiang itself, that authorities have blamed on separatists from the region.
Pictures posted on Sina Weibo, a Chinese equivalent of Twitter, showed victims lying in a tree-lined street, as others sat on flimsy stools.
Flames rose in the background, while other images showed smoke billowing over market stalls behind a police roadblock. None of the photographs could immediately be verified.
Chinese President Xi Jinping pledged to "severely punish violent terrorists", maintain a "strike first" policy and "crack down on them with a heavy fist", state broadcaster CCTV said.
Beijing says it faces terrorism from a violent separatist movement in Xinjiang, driven by religious extremism and foreign groups.
Critics point to economic inequality and cultural and religious repression of Uighurs as drivers of unrest in the vast and resource-rich far western region.
Tianshan described the attack as a "severe, violent terrorist incident".
"Thugs broke through protective metal barrier by driving two vehicles, colliding with the crowd and detonating explosive devices, causing the deaths of 31 people and injuring 94," it said.
A witness at the market told the official news agency Xinhua he heard a dozen "big bangs" during the attack at about 7:50am (2350 GMT Wednesday), when Chinese morning markets are commonly crowded with shoppers seeking fresh groceries.
"I saw flames and heavy smoke as vehicles and goods were on fire while vendors escaped leaving their goods behind," wrote one Weibo poster who said he was less than 100 metres (yards) from the scene.
Increasing technical abilities
China has repeatedly blamed violence in the region on separatist groups seeking independence for Xinjiang, but few analysts consider there have been any credible claims of responsibility for the attacks.
On April 30, the final day of a visit by Xi to the region, assailants armed with knives and explosives carried out an attack at a railway station in Urumqi, killing one person and wounding 79. Two attackers also died.
In March knifemen went on a stabbing spree at a railway station in Kunming, in southwestern China around 2,500 kilometres (1,500 miles) away from Urumqi, killing 29 people and wounding 143 in an incident dubbed "China's 9/11" by state media. Four of the assailants were shot dead by police.
Recent incidents have shown the attackers' "technical and organisational skills are increasing", Shan Wei, a political scientist at the National University of Singapore's East Asian Institute told AFP.
"They can choose the site and timing of attacks, and the challenge to the Chinese government is increasing very fast," he added. "Every time its response is to crack down."
Thursday's blasts came a day after state media reported that courts in Xinjiang jailed 39 people for up to 15 year for offences including spreading "terrorist videos".
"Quite a number of these attacks have no relation to separatist movements, it's venting frustration at the Chinese government... including restrictions on religion," said Willy Lam, a China analyst at the Chinese University of Hong Kong.
"We have reached a vicious cycle because there is no dialogue between Uighurs and Beijing authorities," he added.
In 2009 riots erupted in Urumqi between Uighurs and Han Chinese, the country's ethnic majority, leavin