China said on Monday "illegal" beaching of Philippine warships at the Nansha islands in the South China Sea had "gravely damaged" the coral reef ecosystem in the area, as both countries tussle over disputed territory at atolls in the vast waterway.

China's Ministry of Natural Resources, in a comprehensive report, said Philippine warships have been "illegally beached" around Second Thomas Shoal near Nansha Islands for a long time, "and it has seriously damaged the diversity, stability and sustainability of the reef ecosystem."

There was no immediate comment from the spokespersons of the Philippine Coast Guard and Philippine Navy on China's claims or China's report.

The countries have bickered extensively over the Spratly Islands - called Nansha Islands by China - the Second Thomas Shoal and Sabina Shoal. These small islands are located in the vast waterway, a conduit for more than US$3 trillion of annual shipborne commerce.

The Philippines has soldiers living aboard a rusty, aging warship at the Second Thomas Shoal, which was deliberately grounded by Manila in 1999 to reinforce its maritime claims.

The report proposes that the Philippines should remove the "illegal" beached warships to eliminate the source of pollution and avoid continuing to cause sustained and cumulative harm to the coral reef ecosystem.

China claims most of the South China Sea as its own territory. Beijing has rejected a 2016 ruling by The Hague-based Permanent Court of Arbitration which said its expansive maritime claims had no legal basis

Both sides have reported coral reef damage from ships and fishing vessels operating at certain atolls.

China's report said that from 2011 to 2024 coverage of reef-building corals at the Second Thomas Shoal reef platform declined about 38.2 percent

Last year, the Philippines said it was exploring legal options against China accusing it of destruction of coral reefs within its exclusive economic zone in the South China Sea.

Over the weekend, the Philippines said China's largest coastguard vessel had anchored in Manila's exclusive economic zone in the waterway, a move meant to intimidate.

Despite ongoing altercations, both countries last week agreed for the need to "restore trust" and "rebuild confidence" to better manage maritime disputes.

(Reuters)

An aerial view shows the BRP Sierra Madre on the contested Second Thomas Shoal, locally known as Ayungin, in the South China Sea, March 9, 2023.

China says Philippine warships 'damaged' reef at atoll in South China Sea