Philippines accuses China of poisoning disputed waters to dislodge military outpost

MANILA – The Philippines has confirmed that Chinese boats in 2025 used cyanide that threatens the stability of one of its remote military outposts in the disputed South China Sea, as well as the safety of its soldiers.

Beijing claims the strategic South China Sea in nearly its entirety, despite an international ruling that its assertion has no legal basis.

The Philippine National Security Council (NSC) alleged that the poisoning began in 2025 around Second Thomas Shoal in the Spratly chain, which sits near vital shipping lanes and is reputedly rich in minerals.

“The use of cyanide on Ayungin Shoal is a form of sabotage that seeks to kill local fish populations, depriving navy personnel of a vital food source,” NSC assistant director-general Cornelio Valencia told reporters, using the Philippines’ term for the reef.

The actions also “threaten our navy personnel” through exposure to contaminated water, eating poisoned fish, as well as eroding corals, he added.

Manila and Beijing have a long history of maritime territorial disputes in the hotly contested waterway, including a violent clash in June 2024 in which Chinese coast guard personnel wielding knives, sticks and an axe boarded Philippine Navy boats.

China’s Foreign Ministry branded the fresh accusations a “farce”.

It is “completely unbelievable and not even worth refuting”, spokesman Guo Jiakun said at a news conference on April 13.

“The Philippines has illegally harassed Chinese fishing vessels engaged in normal fishing activities, robbing fishing people of their supplies,” he added.

Mr Valencia said Manila raised the alleged poisoning with Beijing at a recent meeting, but has received no formal reply.

The council said the use of cyanide also “compromises” the stability of BRP Sierra Madre, a World War II-era ship that has been grounded in contested waters for more than two decades and now serves as a Philippine military outpost.

Philippine Navy spokesman Roy Vincent Trinidad said Filipino troops seized 10 bottles of cyanide from sampan boats launched from Chinese fishing ships in February, July and October 2025.

He said soldiers observed another Chinese sampan crew poisoning waters near the shoal in March, adding that the shoal’s waters later tested positive for cyanide.

None of the troops aboard the warship have tested positive for the poison, he added.

Mr Valencia and Rear-Admiral Trinidad both alleged that the fishermen’s mother ships worked for the Chinese navy.

Mr Valencia said the NSC planned to submit a report to the Philippine Foreign Ministry next week that could become the basis for a diplomatic protest.

Manila has also ordered the navy and coast guard to step up patrols “to prevent further environmental harm” in the area, he added. AFP, BLOOMBERG