“It rammed into our coastguard ship 4301 and sunk, all eight of the crew have been rescued,” the coastguard spokesman Zhang Jun said.

He added that the crew had confessed to illegally entering Chinese waters and dangerous manoeuvres.

The sailors have been handed over to the Vietnamese authorities.

“We have urged Vietnam to take measures to avoid similar incidents from happening in light of the increasingly frequent illegal fishing activities in Xisha waters,” Zhang said, using the Chinese name for the Paracel Islands.

“China’s coastguards will also step up control in curbing these illegal activities,” he added.

Chinese ship, Vietnamese fishing boat collide in South China Sea

But Vietnam rejected Beijing’s account. Its foreign ministry said on Saturday that the Vietnamese fishing vessel had been rammed and sunk by the Chinese vessel.

“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.

The ministry said it had lodged a protest against Beijing, and the Vietnam Fisheries Society said all the fishermen were picked up by the Chinese vessel and transferred to two other Vietnamese fishing vessels operating nearby.

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

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

A Chinese oil survey vessel conducted operations in Vietnamese-controlled waters for more than three months last year, prompting a stand-off with Vietnamese ships.

Beijing claims almost all of the South China Sea as its territory and has built artificial islands with military capable facilities over reefs and outcrops in the area, which are also claimed in part by Vietnam.

The South China Sea Probing Initiative, a think tank affiliated with Peking University, said 569 Vietnamese vessels had engaged in illegal activities in the disputed waters in March, a marked increase from 311 in February.

Hundreds of Vietnamese fishing boats intrude into Chinese waters, think tank claims

China and its Southeast Asian neighbours often run into fishing disputes.

Tensions between China and Indonesia are also simmering following a series of incidents over fishing activities in the North Natuna Sea.

Indonesian officials down played the incidents, but critics said China was acting more aggressively and had violated Indonesia’s sovereign rights.

Additional reporting by Reuters