Beijing hit back yesterday at US Navy claims of harassment, saying a US surveillance ship had violated international and Chinese law inside China's exclusive economic zone. The incident off Hainan Island was first reported by the US Defence Department on Monday, on the eve of a visit to Washington by Foreign Minister Yang Jiechi. In response to Washington's claims that five Chinese ships, including a naval vessel, harassed the USNS Impeccable in international waters near Hainan Island on Sunday, the Foreign Ministry said yesterday that the US ship had violated international and Chinese law. 'The US accusations are gravely inaccurate and it confuses what is right and what is wrong,' ministry spokesman Ma Zhaoxu said. 'This is totally unacceptable to China.' Citing the United Nations Convention on the Law of the Sea and relevant Chinese laws, Mr Ma said the US vessel was in China's exclusive economic zone without authorisation, and had thus violated the laws. Washington said the Impeccable, one of five US Navy surveillance ships used to detect and track undersea threats, was operating in international waters 75 nautical miles south of Hainan Island when the incident took place. Washington has yet to ratify the UN convention. The US Defence Department said Chinese vessels surrounded and harassed the US navy ship. At one point one of the ships closed to within 8 metres and Chinese crew members stripped to their underwear, the US reports said. The Chinese crew members reportedly waved Chinese flags at the US vessel and told it to leave the area. Pentagon spokesman Stewart Upton was quoted by Associated Press as saying that the Chinese vessels' activities were unprofessional and violated international law. Mr Ma declined to further elaborate on what exactly happened, but said China had made serious representations to the US. 'China demands the US stop those activities, and adopt effective measures to avoid similar incidents from happening again,' he said. Speaking on the sidelines of the annual meeting of the National People's Congress, Rear Admiral Wang Dengping, political commissar of the PLA Navy Armament Department, said: 'Our civilian and military vessels have the right to do things in our exclusive economic zone. 'We also allow other countries' navies to conduct harmless activities in those areas. But anything that hurts our sovereignty will not be tolerated.'