China’s People’s Liberation Army Navy said it “tracked, warned and expelled” the U.S. destroyer USS Higgins after the vessel entered waters around Scarborough Shoal on Wednesday. The Southern Theater Command said it dispatched forces, including Type 22 missile boats, to monitor the ship, calling the transit an illegal intrusion that “seriously violated China’s sovereignty and security.” The U.S. Navy’s Seventh Fleet rejected Beijing’s account, saying the Higgins was conducting a lawful freedom-of-navigation operation and that China’s statement was “false.” Washington maintains that international law allows its warships to sail near the shoal, which lies inside the Philippines’ exclusive economic zone but is claimed by Beijing. It is the first publicly known U.S. operation inside Scarborough Shoal’s waters in six years and came two days after a Chinese destroyer and coast-guard vessel collided while reportedly trying to block a Philippine patrol ship. Manila said the Chinese vessels’ “hazardous” maneuver damaged both ships and drew protests from Japan, Australia and New Zealand. Tensions escalated further on Wednesday when a Chinese J-15 fighter closed to roughly 200 feet of a Philippine Coast Guard aircraft carrying journalists over the reef. Philippine officials said the encounter lasted about 20 minutes. During the same period, the Higgins and the littoral combat ship USS Cincinnati were sighted roughly 30 nautical miles from the shoal. Scarborough Shoal lies about 124 miles west of the Philippine island of Luzon and is valued for its rich fishing grounds and strategic position on a route that carries more than US$3 trillion in annual trade. A 2016 international tribunal ruled that China’s expansive South China Sea claims have no legal basis, but Beijing continues to assert control and maintain a constant maritime presence in the area.