The Philippines opened a new coast guard base on Thitu Island to strengthen its presence in the disputed South China Sea.

Officials said the base will help defend sovereignty, protect fishermen, and support patrol and rescue operations.

The island is also claimed by China, as well as Vietnam and Taiwan, and has seen frequent tensions between Chinese and Filipino vessels.

China continues to assert broad claims over the sea despite a 2016 South China Sea arbitration ruling rejecting them, NBC News has reported.

The move is seen as a response to China’s growing military presence and activity in the region.