Chinese ship rams, sinks Vietnamese boat

Vietnamese fishing boat has sunk after it collided with a Chinese vessel near a controversial oil rig in the South China Sea, amid tensions between the two nations. Both countries are blaming the other for the incident. Vietnam's coast guard said the boat was encircled by 40 Chinese vessels before it was rammed, reports said.
Background:
Vietnam boat sinks after collision with Chinese vessel [BBC]
Vietnam boat capsized after harassing Chinese ship: Xinhua [Reuters]