Eight "attackers" have been shot dead during an assault on a police station in China's Xinjiang, according to authorities who have blamed "terrorists" for a string of incidents in the largely Muslim region.
Here is a chronology of key events related to the restive region since 2009:
25 June -- A huge brawl erupts in the city of Shaoguan in southern China's Guangdong province between ethnic minority Uighur and Han Chinese factory workers. Two Uighurs are reported killed and dozens injured.
5 July -- Uighurs gather in Urumqi to protest over the Shaoguan incident but violence erupts after security forces move in. Hundreds, perhaps thousands, of Uighurs riot.
6 July -- Chinese security forces begin to pour into Urumqi and fan out across Xinjiang. The Xinjiang government blames exiled Uighur dissident Rebiya Kadeer for orchestrating the unrest. Kadeer, other Uighur exiles and Uighurs in Urumqi blame Chinese authorities for provoking violence.
7 July -- The government says nearly 200 people died in the unrest, with more than 1,600 injured and hundreds arrested.
2 September-- Han residents take to Urumqi's streets for several days of protests calling for a crackdown over a wave of syringe stabbings. The government eventually says nearly 500 were stabbed. Beijing blames "ethnic separatist forces". At least 75 are later reported arrested for the attacks.
9 November -- China says it has put to death the first nine people over the July unrest. Eventually at least 26 are reportedly sentenced to death.
24 June -- Police say they broke a Xinjiang "terrorist" ring behind a string of deadly attacks in the region, arresting at least 10 people.
18 July -- Police kill 20 protesters in clashes in Hotan in southern Xinjiang, exiled Uighur groups say. State press say police fired on demonstrators after they attacked a police station, killing one officer.
31 July-1 August -- Two attacks by alleged terrorists leave 13 people dead in a Han Chinese section of Kashgar, while police kill eight suspected Uighur separatists. State press reports the suspects were trained in terrorist cells in neighbouring Pakistan.
15 September -- Courts in Xinjiang sentence to death four Uighurs convicted of involvement in the July incidents.
28 December -- Police kill seven "terrorists" in a hostage standoff that left one officer dead in Pishan county. State media calls them terrorists engaged in a "holy war."
28 February -- Rioters armed with knives kill at least 10 people in Yecheng, while police shoot two of the attackers dead, state press say. One man is later sentenced to death.
20May -- Police detain a 12-year-old boy in Korla city after a raid on an illegal Islamic school. Overseas activists later accuse police of beating the boy to death. Police say the death was related to a beating received at the school.
29 June -- Six Uighur men try to hijack a plane that had taken off from Hotan and are thwarted by passengers and crew. Two of the men die in the struggle, and 24 crew members and passengers are injured. In December, a court sentences three of the remaining men to death, and a fourth is given a life prison term.
23 April -- Gunfights break out in Bachu county, leaving 15 police and community workers and six "terrorists" dead. Two men are later sentenced to death over the unrest.
26 June -- At least 35 people are killed when, according to Xinhua news agency, "knife-wielding mobs" attack police stations and other sites in Turpan city's Lukqun township before security personnel arrive and open fire. Three people are later sentenced to death.
20 August -- A Chinese policeman is killed in an incident in Yilkiqi described by state media as an "anti-terrorism" operation. Overseas media report, however, that 22 Uighurs were shot dead in the confrontation, which they label a raid.
28 October -- A sport utility vehicle ploughs into pedestrians and bursts into flame near Beijing's Tiananmen Square, killing two tourists and injuring another 40 people in what officials call a terrorist attack. All three people inside the vehicle, identified by authorities as a man, his wife and his mother, all from Xinjiang, die.
17 November -- Two police officers and nine attackers are killed in an attack on a police station in Serikbuya, near Kashgar, state media say. Rights groups say the clash erupted after a Uighur youth was shot dead during a protest.
16 December -- Sixteen people -- 14 Uighurs and two police officers -- are killed in a clash in Shufu county. Authorities describe the slain Uighurs as members of an extremist group, but campaigners say police raided a house where a family was preparing for a wedding and that six women were among those killed.
30 December -- An assault on a police station in Yarkand leaves eight attackers dead, according to the Xinjiang government's official website.