The Taiwanese coast guard says it will conduct a live-fire drill in a hotly disputed region of the South China Sea next month.

The coast guard said the exercise will take place on Taiping, a Taiwan-controlled island among the Spratlys, a large group of islands Taiwan, China, Vietnam, Malaysia, the Philippines, and Brunei claim whole or partial sovereignty over.

Taiping is the largest of the Spratly Islands, known as Nansha in Chinese. Taiwan said the drill is to test new artillery and mortars.

Taiwan’s announcement is expected to further heighten tension in the South China Sea, as it comes amid escalating diplomatic conflict among the nations that lay claim to the islands.