Vietnamese and Chinese ships have collided in disputed waters of the South China sea, causing damage to several boats, injuring crew members and creating political tension, the Vietnamese Coast Guard reported.

The incident occurred when Vietnam’s law enforcement ships tried to stop the illegal intrusion of Chinese escort vessels into the country’s continental shelf, and to prevent Beijing from erecting an oil rig in the South China Sea.

The Vietnamese ships were aggressively fired at with a water cannon and rammed by Chinese vessels, damaging the boats and injuring several crew members.

Vietnam coast guard vice-commander Ngo Ngoc Thu was quoted by The Guardian as saying: "Our maritime police and fishing protection forces have practised extreme restraint. We will continue to hold on there."

"If [the Chinese ships] continue to ram into us, we will respond with similar self-defence."

"But if (the Chinese ships) continue to ram into us, we will respond with similar self-defence."

The clash took place on an international shipping line that runs through Vietnam’s exclusive economic zone, according to Vietnam’s Ministry of National Defence.

On 1 May, Vietnamese agencies detected that China’s Hai Yang Shi You 981 deep-sea rig was being escorted by three oil and gas service vessels to the south of the Hoang Sa (Paracel) archipelago.

Chinese foreign ministry spokeswoman Hua Chunying stated that the oil rig was in China’s territorial waters and therefore drilling is "normal and legal".

"The disruptive activities by the Vietnamese side are in violation of China’s sovereign rights," Chunying added.