At least 27 people were killed Wednedsay when a gang went on a rampage through a town in China's restive northwestern province of Xinjiang. Men brandishing knives attacked police stations, government buildings and a construction site in Lukqun, located 120 miles (200 km) east of Urumqi, the regional capital of the vast Turkic-speaking  region.

According to the state-run Xinhua News Agency, nine police officers and security guards, along with eight civilians, were killed before authorities shot and killed 10 of the attackers. Local Communist Party officials said the attacks began around 6 a.m. local time when rioters attacked people in a stabbing spree and set police vehicles on fire.

While the news agency did not clarify what specifically prompted the mob attacks, this isn’t the first time the region has experienced violent rioting. In July 2009, almost 200 people were killed during riots that erupted in Urumqi between local residents, most of whom are Muslim Uighurs, and the Han Chinese, the nation’s dominant ethnicity. During the unrest at least 828 additional people were wounded, amid widespread destruction and looting. Many called the rioting the worst ethnic unrest in China since the Cultural Revolution in the 1960s.

Some suggest that the new riots are a reaction to increased security in the region as the July 5 anniversary of the 2009 incident approaches. Beijing has stepped up police surveillance, and reportedly put additional forces in place ahead of the anniversary.

Clashes between the Uighurs and the Han or authorities are not uncommon. This past April, 21 people died in Kashgar, China’s westernmost city, in a shootout between armed Uighurs and police. The indigenous Uighurs, who are related to the peoples of ex-Soviet Central Asia, accuse the Chinese government of marginalizing their different culture, language and religion.

According to a report by the Financial Times, Beijing has made efforts in the past to co-opt the indigenous population by pouring government investments into the region. But the Uighurs claim the development benefits only Han Chinese migrants. The British paper reported said that in multiple interviews in 2009, many in Xinjiang expressed resentment toward Han Chinese and longed for independence. Uighurs are also claiming that Beijing has deliberately encouraged Han Chinese immigration to overwhelm them by numbers.

According to Sky News, heavy additional police presence descended on the township as news of the riots gained traction on social media. It wasn’t long before search results for the words "Xinjiang" or "Lukqun" in both English letters and Chinese characters were blocked on Chinese search engines.