HANOI -- A Chinese vessel rammed and sank a Vietnamese fishing boat off the coast of Vietnam on Monday afternoon, the first sinking of a ship in the conflict over disputed waters in the South China Sea.

The state-run Tuoi Tre newspaper reported the incident online. Chinese and Vietnamese ships have clashed repeatedly since Beijing pushed ahead with the installation of an oil rig early this month in waters claimed by Hanoi.

The boat had sailed from the city of Da Nang for a fishing expedition. At about 4 p.m. local time, it was surrounded by 40 Chinese ships roughly 31km from the site of the rig and rammed violently. The boat took severe damage and sank, but the 10 crew members were rescued by other fishing vessels.

A standoff between 113 Chinese ships and 60 Vietnamese vessels in the same waters continued Monday. The Chinese boats have been crashing into and firing water cannons at the Vietnamese ships, and a Vietnamese fisheries surveillance ship was also damaged.

The area remains very tense, according to Vietnam's coast guard.