Philippines installed navigation buoys within its Exclusive Economic Zone in order to assert sovereignty over disputed Spratly Islands located in the South China Sea, Reuters reports, citing a Philippine Coast Guard official.

The move came amid China's increasingly aggressive actions in the South China Sea.

The Philippine Coast Guard said it deployed five buoys with the national flag on May 10-12 in five areas within the 322-kilometer zone, including Whitsun Reef, where hundreds of Chinese ships docked in 2021.

"This move highlights the Philippines' unwavering resolve to protect its maritime borders and resources and contribute to the safety of maritime trade," Commodore Jay Tarriela, South China Sea Coast Guard spokesman tweeted.