Photographed through the window of a closed aircraft, an aerial view shows Pagasa Island, part of the disputed Spratly group of islands, in the South China Sea located off the coast of western Philippines Wednesday July 20,  2011. China protested a trip made by Filipino lawmakers to disputed areas in the South China Sea to assert the claim of the Philippines. Ethan Sun, spokesman for the Chinese embassy in Manila, said the trip scheduled was 'against the spirit' of a code of conduct signed by claimants to the areas in 2002. The Spratlys, believed to be rich in oil, mineral and marine resources, are also claimed in whole or partly by Brunei, Malaysia, Vietnam and Taiwan.  (AP Photo/Roley Dela Pena, Pool)

Photographed through the window of a closed aircraft, an aerial view shows Pagasa Island, part of the disputed Spratly group of islands, in the South China Sea located off the coast of western Philippines Wednesday July 20, 2011. China protested a trip made by Filipino lawmakers to disputed areas in the South China Sea to assert the claim of the Philippines. Ethan Sun, spokesman for the Chinese embassy in Manila, said the trip scheduled was ‘against the spirit’ of a code of conduct signed by claimants to the areas in 2002. The Spratlys, believed to be rich in oil, mineral and marine resources, are also claimed in whole or partly by Brunei, Malaysia, Vietnam and Taiwan. (AP Photo/Roley Dela Pena, Pool)

MANILA (Mabuhay) – The Philippines has protested China’s alleged construction activities in a Manila-claimed reef in the disputed South China Sea, Foreign Affairs Secretary Albert del Rosario said Wednesday.

Following another bold Chinese assertion in the contested waters, Del Rosario said Manila sent a note verbale or diplomatic note to Beijing last April to protest what is calls China’s reclamation of Johnson Reef.

The reef, known locally as Mabini Reef, is within the Philippines’ exclusive economic zone and continental shelf as mandated by the United Nations Convention on the Law of the Sea, Philippine officials say.

Both the Philippines and China, along with more than 100 nations, are signatories to the UN treaty.

But Del Rosario said China rejected the Philippine protest, insisting that Johnson Reef is Chinese territory.

China claims the South China Sea nearly in its entirety even as it overlaps with the sovereign jurisdiction of its smaller Southeast Asian neighbors like the Philippines, Vietnam, Malaysia, Brunei and Taiwan. The Philippines refers to parts of South China Sea as West Philippine Sea.

Asked if China is building an airstrip on the reef as what was reported earlier, Del Rosario said: “That’s one possibility.”

“We don’t know exactly what is their intention there,” he said.

Another senior DFA official said that the Philippines raised China’s building activities in Johnson Reef during the recently concluded Southeast Asian leaders summit in Myanmar, as well as Chinese harassment of Filipino fishermen in two Philippine territories – Ayungin (Second Thomas) Shoal and Panatag (Scarborough) Shoal.

Manila has sought international arbitration before a The Hague-based court to try to declare China’s far-reaching claims, which many feared could impede trade and sea and air access and provoke a major military confrontation. (MNS)