China on Friday again urged Vietnam to respect its sovereign rights and jurisdiction over the Xisha Islands in the South China Sea and stop provocative actions.

Foreign ministry spokeswoman Hua Chunying reiterated at a routine press briefing that the Xisha Islands are the inherent territory of China and there are no disputes in this area.

Hua said Vietnam's actions have violated international law, infringed on China's sovereignty and endangered navigational freedom.

Yi Xianliang, deputy director-general of the Department of Boundary and Ocean Affairs at the Foreign Ministry of China, held a press briefing on Thursday with Li Yong, chief executive officer of China Oilfield Services, on China's drilling operations in waters 17 nautical miles south of Zhongjian Island.

Since May 2, Vietnam has carried out intensive disruptions of Chinese company's normal oil drilling in waters administered by China, Yi said.

Vietnam had sent 36 vessels that had rammed Chinese vessels 171 times in five days from May 3 to 7, Yi said.

Yi stressed the waters where the Chinese company was drilling are completely within China's sovereignty, sovereign rights and jurisdiction.

Soon after a Chinese oil rig arrived on May 2, Vietnam dispatched six vessels that deliberately rammed Chinese government ships in an attempt to disrupt the drilling operations, Yi said.

China has repeatedly requested the Vietnamese side follow international practice, heed and respect the navigation notice issued by China's maritime authorities so as to uphold maritime production, operation order and navigation safety, he said. The Chinese ships are government and civil vessels, Yi said, but Vietnam has deployed armed vessels.

China also found scuba divers sent by Vietnam five meters from Chinese government vessels, Yi said, adding that the Vietnamese side even placed fishing nets and large obstacles in the water that not only posed a security threat to Chinese vessels and facilities, but also jeopardized normal navigation security.

The Vietnamese side's disruption of the Chinese company's normal activities have seriously violated Chinese sovereignty, sovereignty rights and jurisdiction, gravely affected the normal order of production and operation and the safety of China's rig, Yi said.