Senior official calls on China to stop ‘creating unnecessary tensions’ and respect the law.

“Under international law, the Philippines has the right to patrol the length and breadth of the West Philippines Sea which necessarily includes Bajo de Masinloc,” National Security Adviser Eduardo Ano said in a statement on Tuesday, referring to the South China Sea and using the Philippine name for Scarborough Shoal.

Ano was responding to a Chinese statement on Monday that a Philippine military ship had “illegally entered” the waters near Scarborough Shoal, which Beijing seized from Manila in 2012 after a months-long standoff.

The islands lie about 220km (137 miles) off the coast of the Philippines and fall within its exclusive economic zone (EEZ), according to international maritime law.

The Philippine ship was on a routine patrol, the statement said.

“It did not illegally enter any space under Chinese sovereignty because Bajo de Masinloc is part of the PH archipelago and EEZ,” it added.

China and the Philippines have been involved in a number of incidents this year, with Manila accusing Beijing of making aggressive efforts to assert its claim to almost the entire South China Sea under its so-called nine-dash line.

Earlier this month, the two countries’ ships were involved in near collisions close to Second Thomas Shoal, which also lies within Manila’s EEZ. Under the United Nations Convention on the Law of the Sea (UNCLOS), that zone extends 200 nautical miles (about 370km) from a country’s coast.

“We urge China to act responsibly, respect UNCLOS … and stop its aggressive and illegal actions in PH waters,” Ano said.

After China seized control of Scarborough Shoal, the Philippines took its case to the Permanent Court of Arbitration in The Hague.

The court ruled in the Philippines’ favour, concluding that UNCLOS “superseded any historic rights or other sovereign rights or jurisdiction in excess of the limits imposed therein”.

Beijing, although a signatory to UNCLOS, has not recognised the ruling and has stepped up its claims to the waters building artificial islands, expanding military outposts and deploying its coastguard, maritime militia and fishing fleet.