Vietnam has made "brutal and unjustified disruptions" to China's normal, legitimate oil rig drilling and has unilaterally established dozens of drilling platforms in disputed waters, a senior Chinese diplomat said on Friday.

Ouyang Yujing, director-general of the Chinese Foreign Ministry's Department of Boundary and Ocean Affairs, told reporters that Vietnamese vessels have instigated collisions with Chinese ships in waters around a Chinese oil rig 510 times since May 2.

On May 13 alone, as part of Vietnam's harassment and intimidation, the Vietnamese vessels rammed Chinese ships 169 times, while the Chinese were present solely for the protection of Chinese facilities and personnel, he said.