Two persons were known to have been killed in a series of explosions that rocked Kuqa county in China's remote Xinjiang Uygur Autonomous Region early Sunday morning, Xinhua quoted local sources as saying. Casualties of the incident may still rise, the sources said. The explosions occurred between 3:20 a.m. and 4 a.m. in downtown Kuqa, a major town in southern Xinjiang, the witnesses said, adding they saw flashes of fire and heard sporadic gunshots after the explosions. Police has cordoned off the area where the explosions occurred, the witnesses said. Local military sources confirmed the incident and said the military force have been put on alert. The incident follows an attack on border police in Kashi Monday, resulting in the death of 16 police officers and the injury of 16 others. A man drove a truck into a team of more than 70 police officers who were doing regular morning exercise outside the police station. At the same time, another man threw an explosive device toward the gate of the police station and brandished a knife at officers who had been run over by the truck. The two attackers were detained on the spot. Xinjiang police have described the attack as an well-planned terrorist attack.