At least 18 people died after ethnic Uighurs in northwestern China's Xinjiang province attacked the police with knives and bombs at a traffic checkpoint.The attack followed a government order banning a part of the region's population from fasting during the Muslim holy month of Ramadan, reports Efe.Suspects killed several police officers with knives and bombs after speeding through a traffic checkpoint in a car in Kashgar's Tahtakoruk district, US-based Radio Free Asia said, citing Turghun Memet, an officer at a nearby police station.Armed police responded to the attack and killed 15 suspects “designated as terrorists,” Memet said.The attack comes at the beginning of the Muslim holy month of Ramazan, a sensitive time in Xinjiang after an uptick in attacks over the past three years in which hundreds have died, blamed by Beijing on Islamist militants.Exiled Uighur groups and human rights activists say repressive government policies in Xinjiang, including controls on Islam and on Uighur culture, have provoked unrest, a claim that Beijing denies.