Vietnam has accused China of sinking one of its fishing boats near disputed islands in the South China Sea that could further raise tensions between the Communist neighbors.

Phan Huy Hoang, an official in central Quang Ngai province where the fishermen came from, said Thursday that a Chinese vessel slammed into the fishing boat with 10 fishermen on board near the Paracels islands on Sept. 29 and sank it. The fishermen were rescued by another Vietnamese fishing boat and the case was reported to authorities when the fishermen returned home two days ago.

Hoang says more than 20 Vietnamese fishing boats have been attacked by Chinese vessels this year.

He says a formal protest will be made to China.