In one of the deadliest reported attacks in China in years, two men aimed a lorry at police officers jogging near their barracks in Kashgar, a city in the Xinjiang region, the Xinhua news agency said.
After the lorry hit a roadside pole, the two got off and threw home-made explosives at the barracks, moving in to hack at police officers with knives, the agency reported.
It said 14 police were killed on the spot and two died from their wounds on the way to hospital, while 16 others were injured.
Both attackers were arrested, one of them with a leg injury sustained during the raid, according to the news agency.
Xinhua said debris from five explosives was found near the barracks.
"The raid... was suspected as a terrorist attack," the agency said, citing local police in the city, which is close to the Tajikistan border and around 4,000 kilometres (2,500 miles) from Beijing.
The incident threw a shadow over the Olympic countdown, after government warnings that members of Xinjiang's Ui