The Philippine military and coast guard concluded a five-day joint maritime exercise with the United States in the West Philippine Sea on Saturday, drawing an immediate, intensified patrol response from Beijing.

The Bilateral Maritime Cooperative Activity, which ran from 26 to 30 May, took place in the vicinity waters of Bajo de Masinloc, also known as Scarborough Shoal.

The drills marked the third joint operation between the two nations this year, aimed at deepening defense ties and strengthening maritime awareness, the Armed Forces of the Philippines (AFP) reported Sunday.

The exercises featured high-level allied assets, with the Philippines deploying the frigate BRP Antonio Luna, a coast guard patrol ship, and multiple aircraft including FA-50 fighter jets.

Meantime, the US Indo-Pacific Command participated with the Coast Guard Cutter Midgett and an MH-65 helicopter. Over five days, allied forces conducted search-and-rescue drills, helicopter deck landings, communication exercises and mock visit-and-board operations.

Following the conclusion of the drills, Beijing visibly ramped up its military and law enforcement presence around the strategic atoll.