Chinese coast guard ships and a Chinese navy helicopter harassed a group of Philippine fisheries vessels conducting a scientific survey in a hotly disputed area of the South China Sea, forcing them to cancel the operation, the Philippine coast guard said on Saturday. 

The incident took place near Sandy Cay, three small uninhabited sandbars flanked by an artificial island base of Chinese forces and a Philippines-occupied island in the Spratlys archipelago, the coast guard said.