Chinese ships were locked in two separate confrontations with Vietnamese vessels near a controversial South China Sea oil rig on Sunday.
The first incident happened at around 12.30pm, according to a report on China National Radio’s military channel, when a Chinese coastguard ship blasted water at a Vietnamese fishing inspection vessel.
Five minutes later, the Vietnamese boat, with decal 635, fled, the radio report said.
Two other Chinese vessels blocked support units deployed by Vietnam’s coastguard to help the distressed ship, it said.
Watch: Vietnamese media's footage of the confrontation
Later that day, at around 5pm, a Vietnamese coastguard vessel collided with a Chinese counterpart, leaving the Vietnamese boat damaged.
The report identified the Vietnamese boat as CS B-2016 and the Chinese boat as 46015.
The Vietnamese boat had four leaks on the right side of the gunwale and was tilting, according to the China National Radio report, while equipment including two air pipes and a pump hose were destroyed.
The captain of the damaged ship told a Vietnamese television station that, after the collision, they had to escape a fleet of Chinese boats that surrounded them.
When they were in the clear, they were able to make repairs.
“With these kinds of holes, if we were to meet a [strong] wave after the machine stopped working, water will fill the boat if it moves,” he said.
“Therefore, after escaping the Chinese vessels wisely – they were chasing and surrounding us – [we] immediately started to fix damage on the 2016 coastguard vessel.”
A photo reportedly of the damaged ship showed it was almost submerged, with only the prow and tophouse above the surface.
This marks the second time since May 26 that a Vietnamese boat has reported damage sustained from advancing Chinese vessels.
Previously, a Chinese fishing vessel was accused of ramming and sinking a small Vietnamese fishing boat, carrying 10 fishermen, some 17 nautical miles off the oil rig.
Chinese Foreign Ministry spokesman Hong Lei today accused the Vietnamese side of interfering with drilling operations and "ramming against" the Haiyang Shiyou 981 rig "on many occasions".
"[We urged them to] stop intruding China's sovereignty and jurisdiction, and immediately pull out its vessels ... and personnel," Hong said. "However, so far, the Vietnamese side ignore our representations and continue with their disruptive actions and ramming into the oil rig."
Hong accused Vietnam of "creating tensions [and] violating the international laws and norms".
Vietnam, in response, is considering legal action over the rig which it says is operating in its economic zone and territorial waters. The platform is located 240km off Vietnam’s east coast and some 370km from the southern mainland tip of Hainan.
The oil rig sparked bloody industrial protests in Vietnam last month, leaving at least six Chinese workers dead.
The June 1 confrontations occurred on the last day of a Shanghai security forum Shangri-La Dialogue, which highlighted tensions over China's maritime sovereignty disputes with its neighbours.
With additional reporting from Teddy Ng in Beijing
Correction: An earlier version of the article mistakenly referred to the Shanghai security forum as CICA, instead of the recently concluded Shangri-La Dialogue.