"Today thugs crashed a car into the public security building of Kargilik county in Xinjiang's Kashgar prefecture and set off an explosion. Police took decisive action and shot dead 13 thugs," the official Tianshan web portal reported.
Police shot dead 13 attackers while three policemen were injured, the state-run Xinhua news agency reported.
The report described those killed as "mobsters" and said that the public security authorities are investigating the incident.
The Xinhua report described the vehicle they rammed into the police station as a truck and said the attack happened in the morning.
Xinjiang is restive for the past several years over native Uygur Muslim's agitation, opposing settlements of Hans from other provinces.
China blames the East Turkestan Islamic Movement (ETIM), an Al Qaeda affiliated group, for a series of attacks in the province and outside.
There have been several blasts and knife attacks in China recently.
At least 39 people were killed and 94 others injured in May in China's bloodiest terror attack at a busy market in Urumqi, provincial capital of the Xinjiang province, when militants rammed two explosive-laden vehicles into a crowd and set off over a dozen blasts.
This attack is regarded as the worst violence in the country as militants, earlier largely confined to knife attacks, used multiple explosives besides triggering car bombs.
In April, Xinjiang was the scene of a railway station attack which killed three and injured 79 people.
That attack was blamed on radical religious extremists seeking to take control of the region.
While in another major incident in March, dubbed by state media as China's "9/11", knife-wielding attackers stabbed 29 people to death and injured 143 at another railway station in southwestern Kunming city.
China has launched a nationwide crackdown on militants from Xinjiang and also firmed up plans with Pakistan to stop infiltration of ETIM militants from across the border of Pakistan-occupied Kashmir (PoK).
Thirteen people were executed on June 16 in Xinjiang for terrorist attacks and violent crimes.
Earlier this month, China sentenced 81 people, including 9 persons to death, and arrested 29 others for terrorism-related crimes in the Xinjiang province.
Karachi airport attack: What makes the Taliban so deadly
50 injured as blast rocks railway station in China's Xinjiang
Russia eyes gas pipeline deal with India
Pak offensive against Taliban kills 184 militants
16 Indians stranded in Iraq moved out, one of the 40 abducted escapes