The military continued its weeklong show of force in the South China Sea with a sortie over the contested waters by two Air Force bombers, stars and stripes reported. The B-1B Lancers from Ellsworth Air Force Base in South Dakota flew a 32-hour round trip to conduct operations over the sea as part of a joint bomber task force by the US Indo-Pacific Command and US Strategic Command, the Air Force said in a statement Thursday. China has claimed sovereignty over much of the South China Sea, an assertion disputed by other nations with competing claims, including Vietnam, the Philippines, Malaysia and Brunei. During the past week, Navy warships operated near the Spratley and Paracel Islands. Two of the archipelagos China has vigorously claimed, the military news outlet reported. The guided missile cruiser USS Bunker Hill sailed near the Spratley's on Wednesday as part of its so-called Freedom of Navigation Operations, intended to challenge assertions by China and others that military passing near the islands must receive authorization. The United States contends that international law allows for direct passage through the contested archipelagos. On Tuesday, the guided missile destroyer USS Barry sailed near the Paracel Islands.