MANILA — The National Security Council (NSC) said laboratory tests confirmed that yellow bottles recovered by the Philippine Navy from Chinese sampans operating near BRP Sierra Madre (LS 57) at Ayungin Shoal contained cyanide.

In a statement, NSC spokesperson Assistant Director General Cornelio H. Valencia Jr. said the bottles were seized in February 2025 and again on October 24, 2025.

The NSC said laboratory examination conducted by the National Bureau of Investigation’s Forensic and Scientific Research Service verified the presence of cyanide in the seized bottles.

“The National Security Council hereby announces that laboratory testing has confirmed that the yellow bottles recovered by the Philippine Navy from Chinese sampans operating in the immediate vicinity of BRP Sierra Madre (LS 57) at Ayungin Shoal tested positive for the presence of cyanide,” Valencia said.

He added that the findings confirm the hazardous nature of the materials. “These laboratory findings remove any doubt as to the dangerous and unlawful nature of these activities,” he said.

The NSC warned that the use of cyanide poses risks to both human health and marine ecosystems, as well as to the safety of Navy personnel stationed at LS 57 and the livelihoods of Filipino fisherfolk.

“The deliberate use of cyanide raises serious concerns of illegal and destructive practices that threaten our Navy personnel in LS 57, the fragile marine environment of the West Philippine Sea, and the livelihood of Filipino fisherfolk,” Valencia said.

He said such actions, if proven intentional, would violate Philippine environmental laws, international maritime standards, and obligations under the United Nations Convention on the Law of the Sea (UNCLOS).

The council also described the alleged use of cyanide as a form of sabotage. “We wish to underscore that the use of cyanide in Ayungin Shoal is a form of sabotage that seeks to kill local fish populations, depriving Navy personnel of a vital food source,” Valencia said.

He added that the chemical could damage coral reefs and potentially affect the structural stability of BRP Sierra Madre.

Ayungin Shoal is within the Philippines’ exclusive economic zone, where the country exercises sovereign rights and jurisdiction, the NSC said, adding that the presence of foreign vessels handling hazardous substances in the area is unacceptable.

The NSC said it has ordered the Armed Forces of the Philippines, the Philippine Coast Guard, and other agencies to increase maritime monitoring, strengthen patrols, and take measures to prevent further environmental damage and protect national security interests.

“Let it be clear: the Philippines will not tolerate any act—whether by state or non-state actors—that endangers its personnel or the marine environment, violates its sovereign rights, or undermines peace and stability in the West Philippine Sea,” Valencia said.