A US guided-missile cruiser operating in international waters in the South China Sea was forced to take evasive action on December 5 to avoid a collision with a Chinese warship, the US Pacific Fleet said in a statement. The incident came as the USS Cowpens was operating near China's only aircraft carrier, the Liaoning, and at a time of heightened regional tensions following Beijing's declaration of an air defence identification zone farther north in the East China Sea. The Pacific Fleet said in its statement on Friday that a second Chinese ship manoeuvred near the Cowpens, forcing the US ship to take evasive action to avoid a collision. "Eventually, effective bridge-to-bridge communications occurred between the US and Chinese crews, and both vessels manoeuvred to ensure safe passage," the defence official said. Asked if the Chinese vessel was moving towards the Cowpens with aggressive intent, the official declined to speculate on the Chinese crew's motivations. However, The New York Times quoted another US official on its website yesterday as saying the Chinese ship "was particularly aggressive". The defence official said the ship - similar to an American tank carrier - had cut across the Cowpens' bow at a distance of less than 180 metres. The near miss was the most significant US-China maritime incident in the South China Sea since 2009, said security expert Carl Thayer at the Australian Defence Force Academy. Heightened tensions over China's military assertiveness have raised concerns that a minor incident in disputed maritime waters, the South China Sea and East China Sea, could quickly escalate. The US has raised the latest incident at a "high level" with the Chinese government, according to a State Department official quoted by the US military's Stars and Stripes newspaper. Analysts said similar frictions might be unavoidable in the future, making a crisis management system that facilitates better military-to-military communication between the two powers ever more urgent. Jin Canrong , of Renmin University's school of international studies, said the frequency of such frictions was set to rise as the Chinese navy was increasing its presence in the South China Sea, where the US navy has also been active. "Of course the leaders of both countries do not want to see confrontation, but young military men on the front line may easily lose their temper," said Jin. Zhuang Jianzhong, deputy director of the Centre for National Strategy Studies at Shanghai Jiao Tong University, said such "tactical encounters" were not likely to dampen the overall bilateral ties between China and the US. "It's in both sides' interests to maintain the security and stability in the Asia-Pacific region," he said. Jin said while the US side had been quite keen on setting up a hotline between the top defence officials, China had been reluctant to do so. "China needs to further improve its military transparency," he said.