China has hit back at claims it violated Vietnam's marine sovereignty in a new spat over disputed areas of the South China Sea, accusing Hanoi of harming Beijing's interests in the region.

Vietnam's state media quoted the foreign ministry Friday as saying Chinese marine surveillance vessels had damaged a ship operated by the state oil and gas firm PetroVietnam, within what it described as its exclusive economic zone.

China's foreign ministry spokeswoman Jiang Yu responded late Saturday that Vietnam had been carrying out oil and gas operations in territorial waters under Beijing's own jurisdiction.

This "harms China's rights, interests and jurisdiction in the South China Sea and violates the consensus reached by the two countries on the South China Sea issue. China opposes this," Jiang said.

"The actions taken by Chinese authorities are normal marine law enforcement and surveillance activities undertaken in territorial waters under China's jurisdiction."

It was unclear whether the Chinese statement related specifically to the latest incident or more generally to Vietnam's activities in the disputed waters.

The Vietnam News Agency report said the Chinese vessels had approached the PetroVietnam ship and cut its exploration cables.

A complaint to the Chinese embassy in Hanoi said the incident "seriously violated Vietnam's sovereignty" and a 1982 United Nations convention on the law of the sea.

Hanoi stood firm on Sunday, with foreign ministry spokeswoman Nguyen Phuong Nga saying Vietnam rejected China's reaction to the spat, insisting that Beijing had "gone against the knowledge of leaders of both countries".

"China is now causing a misunderstanding with the intention of making an undisputed zone into a zone in dispute," she told reporters, also calling for compensation from China for the damage caused.

Beijing and Hanoi have a long-standing dispute in the South China Sea over the sovereignty of the Paracel archipelago and the more southerly Spratlys, both potentially resource-rich outcrops that straddle strategic shipping lanes.

The area where the latest incident allegedly occurred is between the two island chains.

China's increasingly assertive role in the South China Sea has raised tensions with other countries in the region as well as the United States.

The Philippines, Brunei, Malaysia and Taiwan also claim all or part of the Spratlys.