The Philippines has accused Chinese fishermen of pouring cyanide into waters in the Spratly Islands, escalating tensions in the disputed South China Sea where repeated confrontations have taken place between rival vessels.
Beijing continues to claim almost the entire South China Sea, despite an international ruling that its claim has no legal basis under international law.
The Philippine National Security Council (NSC) alleged that the poisoning activity began last year around Second Thomas Shoal, also known locally as Ayungin Shoal, an area near key shipping routes that is believed to be rich in marine resources.
NSC assistant director-general Cornelio Valencia said the alleged use of cyanide was aimed at destroying fish populations, which he described as a food source for Filipino naval personnel stationed in the area.
He also warned that contamination could pose health risks to troops through exposure to polluted waters or consumption of affected marine life, while also damaging coral reef ecosystems.
Manila and Beijing have long been involved in territorial disputes in the region, which has seen several tense and sometimes violent maritime encounters in recent years.
Valencia said the issue had been raised with Chinese officials at a recent meeting, but Manila has not received a formal response. The Chinese embassy has not commented on the latest allegations.
He added that damage to coral reefs could weaken the structural integrity of the BRP Sierra Madre, a World War II-era vessel deliberately grounded by the Philippines in 1999 to assert its territorial claim over the shoal.
Philippine Navy spokesman Rear Admiral Roy Vincent Trinidad said troops had recovered bottles of cyanide from small boats linked to Chinese fishing vessels on several occasions, and claimed further suspicious activity had been observed in recent months.
He added that water samples from the area reportedly tested positive for cyanide, although no Filipino personnel stationed at the shoal have tested positive for poisoning.
Both officials also alleged that some of the fishing vessels involved may have links to the Chinese navy.
The Philippines said it plans to submit a report to its foreign ministry, which could form the basis for a formal diplomatic protest, while also stepping up naval and coastguard patrols to prevent further environmental damage in the area.
