BEIJING (Reuters) -China's military closely monitored and "drove away" USS Halsey that entered the territorial waters of Paracel Islands in the South China Sea on May 10, the Southern Theater Command of the People's Liberation Army said in a statement on Friday. The U.S. move "seriously infringed on China's sovereignty and security," the military said. "It is yet another iron proof of its navigation hegemony and militarization of the South China Sea," it said, adding its troops would stay on high alert and safeguard national security.