The Philippines accused Chinese fishermen of dumping cyanide in disputed South China Sea waters, escalating tensions over the strategic Second Thomas Shoal where Filipino troops maintain a military outpost on a grounded warship.
Philippine security officials said laboratory tests confirmed the presence of the toxic substance in bottles seized by the navy last year from Chinese vessels near the submerged reef in the Spratly Islands. The alleged poisoning campaign began in 2025 and continued into this year.
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
Cornelio Valencia, National Security Council spokesperson — Al Jazeera English
Valencia warned the cyanide could damage coral reefs supporting the BRP Sierra Madre, a rusting World War Two-era vessel deliberately grounded at the shoal in 1999 to assert Manila's territorial claim. The toxic substance also poses health risks to troops through water contamination and poisoned fish consumption.
Philippine Navy spokesman Rear Admiral Roy Vincent Trinidad said troops seized ten bottles of cyanide from sampan boats launched from Chinese fishing vessels during operations in February, July, and October 2025. Military personnel spotted another Chinese crew allegedly poisoning waters near the shoal last month.
Al Jazeera presents a balanced account that gives equal weight to both Philippine accusations and Chinese denials, framing this as part of ongoing territorial disputes. The outlet emphasizes the environmental and military implications while maintaining journalistic distance from either side's claims.