Rioting in western China’s Xinjiang province has left at least 27 dead at the hands of “knife-wielding mobs” according to Chinese authorities. The province, which is home to a significant Uyghur minority, and is among the poorest provinces in the country, has been seen numerous outbreaks of violence over the years, but this is the worst rioting since 2009.

The reasons for the unrest remain unclear. According to the government-controlled media, however, eight civilians and nine police or security personnel were killed by the rioters before police opened fire, killing ten of them. Chinese authorities reported that the rioters were setting police cars on fire and stabbing people. A construction site, local government building, and several police stations were also reportedly attacked.

The Uyghur (alternatively Uigur or Uygur) are a Turkic people and are predominantly Sunni Muslims. There have been numerous reports of oppression of the Uygur at the hands of the Chinese government and, as noted above, the region has seen regular outbreaks of violence over the years. The worst was in 2009, when over 200 people were killed. Twenty-one people were killed in what the government called terrorist attacks in April.

According to a statement by the World Uyghur Congress, communications with the region have been locked down by the Chinese government. The WUC called the official version of events into question. They say that the violence is the result of continued oppression of the Uyghur people by the Chinese government.

It is unclear whether any violence is still ongoing in the region, or whether Chinese authorities have the rioting under control.