By Liz Lagniton | 2025-12-22

China maintained a broad maritime presence in the West Philippine Sea in early December as Philippine and US forces held joint naval drills, Philippine authorities said, with officials reporting that Chinese forces fired flares during a separate, routine Philippine aerial patrol conducted days earlier.

The West Philippine Sea is Manila's name for the part of the South China Sea within the Philippines' Exclusive Economic Zone (EEZ).

Joint drill with US

The December 9–10 joint exercise, the allies' ninth Maritime Cooperative Activity, "provided both forces an opportunity to enhance interoperability, deepen operational cooperation, and strengthen joint capabilities amid evolving security challenges," the Philippine military said in a statement.

For the latest drills, the Philippines deployed the BRP Jose Rizal, three FA-50 fighter jets, three A-29B Super Tucano aircraft, one Philippine air force Black Hawk helicopter and one Sokol helicopter. The military said the assets demonstrated the country's expanding operational readiness and its growing ability to integrate with allied forces in complex maritime scenarios.

The US Indo-Pacific Command sent the guided-missile destroyer USS Rafael Peralta, along with MH-60R Seahawk helicopters and a P-8A Poseidon maritime patrol aircraft. The activity included helicopter cross-deck operations, maneuver exercises, communication checks and shared maritime domain awareness, the US Navy said.

Monitoring Chinese vessels

While the joint drills were under way, Philippine authorities continued to monitor Chinese vessels across multiple features in the West Philippine Sea. Their forces watched at least 20 vessels from the Chinese People's Liberation Army Navy (PLAN) and the China Coast Guard during the first week of December, Rear Adm. Roy Vincent Trinidad, Philippine navy spokesperson for the area, said.

A recent Philippine coast guard (PCG) maritime domain awareness flight documented the presence of 101 Chinese maritime militia vessels, said Trinidad.

He described the vessels as "double-hatted," operating at times as fishing boats and at other times as force multipliers for the Chinese military. Three hundred to 350 such vessels are typically observed in the area at any given time, he said.

Scarborough Shoal, situated 124 nautical miles off Zambales and within the Philippines' EEZ, remained one of the most closely monitored features. Since November, the Philippine navy has observed Chinese naval and coast guard vessels swarming the shoal, one of the largest recent concentrations of Chinese ships in the area.

Philippine authorities said China has increased patrols around the shoal following its unilateral declaration of the area as a "nature reserve," a move protested by Manila.

A Philippine plane flying over the shoal December 11 spotted 2 buoys that the Chinese installed in November, ABS-CBN News reported.

Chinese flares fired

Beyond surface deployments, Philippine authorities reported direct challenges during routine aerial patrols. On December 6, a Bureau of Fisheries and Aquatic Resources aircraft jointly deployed with the PCG recorded video of three flares fired from Subi Reef while it was flying as scheduled over the Kalayaan Island Group.

China has militarized the reef, but the Philippines claims it.

The patrol was lawful and aimed at monitoring fishing conditions, foreign vessel presence and the marine environment, said Cdre. Jay Tarriela, PCG spokesperson for the West Philippine Sea. He described the flare firing as "hazardous and unnecessary," adding that the aircraft was obeying international law.

During the same mission, authorities documented extensive Chinese activity around Subi Reef, including one Chinese hospital ship, two China Coast Guard vessels and 29 Chinese maritime militia vessels anchored near the reef. Subi Reef is part of the Spratly Islands, where China has built large artificial island bases over the past decade.

The December 6 patrol also observed vessels from other countries across the region, including Vietnamese survey and fishing ships, while recording large concentrations of Chinese maritime militia at several disputed features.

The Philippine patrol detected a PLAN vessel near Sabina Shoal. It issued multiple radio challenges to the Philippine aircraft, even though it was operating within areas claimed by Manila.

The monitoring flights are routine transparency missions conducted in accordance with Philippine law, the 1982 United Nations Convention on the Law of the Sea and the 2016 arbitral ruling that invalidated China's expansive maritime claims, said Tarriela. "All safe and mission accomplished," he said, according to the Inquirer.