China told Vietnam on Thursday to stop unilateral oil exploration in disputed areas of the South China Sea and not harass Chinese fishing boats, raising tension in protracted maritime territorial disputes with its neighbors.
Vietnam had already expelled Chinese fishing vessels from waters near China's southern Hainan province, Chinese Foreign Ministry spokesman Hong Lei told reporters.
Hong's description of the confrontation last Friday was in contrast to the account by Vietnam, which said a Vietnamese ship had a seismic cable it was pulling cut by two Chinese fishing ships.
"Vietnam's statement is inconsistent with the facts," Hong said.
China is in an increasingly angry dispute with neighbours including the Philippines, Taiwan, Vietnam, Brunei and Malaysia over claims to parts of the potentially oil and gas-rich South China Sea. China lays claim to almost the whole of the sea, which is criss-crossed by crucial shipping lanes.
The Chinese fishing boats were in an area where Vietnam's claim overlaps with waters of Hainan province, Hong said. New Chinese regulations allow police to board vessels deemed to be intruding in waters off the island of Hainan.
"The relevant fishing vessels were in these waters conducting regular fishing activities and they were unreasonably expelled by Vietnamese military vessels," Hong said.
The South China Sea is one of Asia's most sensitive military hotspots whose profile has been raised by a newly assertive China.
China has become more outspoken in its claims over islands in the South and East China Seas. The mounting disputes come at a time when China is flexing increasing naval might, including the launch of its first aircraft carrier in September and the test flights of its first two models of a stealth jet fighter, one of which is believed to be designed to land on aircraft carriers.
India, which jointly conducts some oil exploration with Vietnam, said this week that it was prepared to send navy ships into the region to safeguard its interests.
Hong said China and Vietnam were currently in negotiations over the waters.
"We hope the Vietnam side will not engage in unilateral oil and gas exploration activities in the relevant waters, cease interfering with Chinese fishing vessels' normal operations, and create a friendly atmosphere for bilateral negotiations", he said.