Clashes between ethnic Uighurs and the police in China's Xinjiang region have killed at least 18 people this week, said reports that were corroborated by local residents and a police officer.
The Washington based Radio Free Asia news service said around 28 people may have been killed in an attack involving knives and bombs in the predominantly Uighur city of Kashgar on Monday, the New York Times reported.
The clashes have has not been reported in Chinese state controlled media.
The reports further suggest that the clash started after a police officer tried to stop a car that was crossing a checkpoint.
The car backed up and ran over the officer's leg while two other unarmed police officers who reached the location were stabbed to death.
More attackers had arrived until the armed police officers reached the scene following which 15 assailants were killed by the police.