Washington, April 22 : Amid a war of words between the US and China over the origin of the coronavirus pandemic, the US Navy said that three of its warships passed through the South China Sea "in support of security and stability", leading to apprehensions of tensions resurfacing in the area. "On watch and ready. The #USNavy's #USSBunkerHill, #USSBarry, and #USSAmerica transit the #SouthChinaSea while operating in @US7thFleet as an Expeditionary Strike Group in support of security and stability in the Indo-Pacific region. #FreeAndOpenIndoPacific," the US Navy said in a tweet early on Wednesday. The America is an amphibious assault ship, the Bunker Hill, a guided missile cruiser, and the Barry, a guided missile destroyer. Australian warship HMAS Parramatta also conducted exercises with the US Navy in the region, the Australian government said. The Defence Department said "over the past few days", the ANZAC-class frigate exercised with the US ships as they passed through the contested region. "HMAS Parramatta has been undertaking an extended deployment throughout South and South-East Asia for the last two months, to help strengthen the stability and security of the region," a Defence spokesperson said. The "show of strength" came as other nations, including littoral countries, express growing concerns with China's expansion in the region. China, which had over the weekend announced that it had formally established two new districts in the South China Sea, has not expressed any reaction yet. /IANS