HANOI--Vietnam has lodged an official protest with China following the sinking of a Vietnamese fishing boat it said had been rammed by a Chinese maritime surveillance vessel near islands in the disputed South China Sea.

The Vietnamese fishing vessel, with eight fishermen onboard, was fishing near the Paracel Islands on Thursday when it was rammed and sunk by the Chinese vessel, Vietnam's foreign ministry said in a statement posted on a government website on Saturday.

All the fishermen were picked up by the Chinese vessel alive and were transferred to two other Vietnamese fishing vessels operating nearby, the Vietnam Fisheries Society said in a statement posted to its website.

"The Chinese vessel committed an act that violated Vietnam's sovereignty over the Hoang Sa archipelago and threatened the lives and damaged the property and legitimate interests of Vietnamese fishermen," the foreign ministry said in its statement, referring to the Paracel Islands by its Vietnamese name.

Vietnam and China have for years been embroiled in a dispute over the potentially energy-rich stretch of water, called the East Sea by Vietnam.

The Vietnamese boat illegally entered the area to fish and refused to leave, the Chinese coast guard said late on Friday.

After making some dangerous maneuvers, the boat collided with a Chinese patrol vessel and sank, the Chinese coast guard said in a statement on its social media account.

The Chinese coast guard also said it had made solemn representations with the Vietnamese side.

The incident marks the second time in less than a year a Vietnamese fishing vessel has been reportedly sunk by a Chinese vessel near the China-controlled Paracels.

A Chinese oil survey vessel conducted operations in Vietnamese-controlled waters for more than three months last year, causing a tense standoff between vessels from the two countries.