The Philippine Coast Guard (PCG) on Monday accused Chinese vessels of issuing multiple radio challenges and jamming satellite signals during a routine maritime patrol near Bajo de Masinloc in the West Philippine Sea (WPS).

Commodore Jay Tarriela, the coast guard’s spokesperson for the West Philippine Sea, told reporters in a video briefing that the interference targeted a PCG Islander aircraft dispatched from Manila at 7 a.m.

The flight was launched to monitor a large fleet of Filipino fishing boats operating near the shoal, also known as Scarborough Shoal.

Tarriela said three China Coast Guard vessels issued radio challenges during the flight. He also cited that a Chinese Navy warship issued two separate challenges while positioned approximately 75 nautical miles off the coast of Zambales, an area located within the Philippines’ 200-nautical-mile exclusive economic zone.

Beyond the radio warnings, Philippine officials reported that their communications were compromised. 

The WPS spokesperson said the crew suspected the Chinese vessels engaged in signal jamming after the aircraft’s Starlink internet link failed, hindering the ability to coordinate with other Philippine government agencies.

He added that the mission was supported by the Bureau of Fisheries and Aquatic Resources, which deployed four vessels to the area.