In a clear retaliation to the Philippines’ enactment of two territorial seas laws, China has published baselines for a disputed shoal in the West Philippine Sea that it had illegally seized from Filipinos.

China’s move may upgrade tensions over the territorial claims of the two countries, international observers warned.

On Friday (November 8) , President Ferdinand Marcos Jr. signed into law Republic Act No. 10264 or the Philippines Maritime Zones Act and RA 12065 or the Philippine Archipelagic Sea Law.

China quickly condemned the move by summoning the Philippine ambassador to receive its formal protest over the move in the Philippines.

On Sunday, the Chinese Foreign Ministry posted online the geographic coordinates for the baselines around Scarborough Shoal which it had seized notwithstanding a 2016 ruling by the international arbitration court invalidated most of Chinese claims to the South China Sea or West Philippine Sea.

The Foreign Ministry defended is decision, claiming that it is in accordance with a UN Agreement and an existing law.

“This is a natural step by the Chinese government to lawfully strengthen marine management and is consistent with international law and common practices,” the Foreign Ministry statement said.

Particularly, the Chinese government identified RA 10264 as violative of its sovereignty in the South China Sea.

“China firmly opposes it and will continue to do everything necessary in accordance with law to firmly defend its territorial sovereignty and maritime rights and interests,” the Foreign MInistry added.