The Philippines is protesting against what it calls "sovereignty patrols" by China around a disputed, oil-rich reef, saying that these are part of an emerging pattern meant to "change the status quo" in the South China Sea.
In a news briefing yesterday, Mr Charles Jose, the Philippines' Foreign Ministry spokesman, said that the patrols earlier this month by two Chinese survey ships around Reed Bank, a mostly submerged reef in the South China Sea about 144km from the nearest Philippine coast, are "not just an innocent exercise of freedom of navigation".
They are "part of a pattern of illegitimate sovereignty patrols" within the Philippines' 370km exclusive economic zone, he said, adding that an official protest will be lodged with the Chinese Embassy as soon as possible.
Reed Bank is about 85 nautical miles from the western Philippine island of Palawan, well within Manila's exclusive economic zone, while it is 595 nautical miles from the coast of China's Hainan island, he pointed out.
"We see an emerging pattern of constant and overwhelming presence pursuant to China's unilateral effort to change the status quo," Mr Jose told reporters.
He cited China's land reclamation work in at least five reefs in the disputed Spratlys, a group of shoals, atolls and islets in the South China Sea just west of Palawan, as part of this pattern.
Mr Jose's comments came after the presence of the two hydrographic research vessels around Reed Bank was first disclosed by President Benigno Aquino in a TV interview on Sunday.
Asked if the vessels suggested that China is preparing to move an oil rig near Philippine shores, Mr Jose said: "We cannot speculate about that at the moment."
Territorial disputes in the South China Sea - which is claimed almost entirely by China but also in part by the Philippines, Vietnam, Malaysia, Brunei and Taiwan - have heightened tensions in recent months.
Earlier this year, Chinese state-owned oil firm CNOOC placed an oil rig 80 nautical miles deep in Vietnam's exclusive economic zone, sparking skirmishes at sea and anti-Chinese riots in Vietnam.
China has since removed the rig, saying that its mission there has been completed.
The Philippines has been attempting to drill for oil and gas around Reed Bank, but Britain-based Forum Energy, the company granted an exploration permit, has had to hold back after a survey ship it sent was nearly rammed by a Chinese vessel in 2011.
Forum, a partner of Philippine mining giant Philex, has said it is open to jointly exploring the area with CNOOC.
But Mr Jose said any joint venture covering Reed Bank "would have to be under our laws, our terms, our Constitution".
During the ASEAN Regional Forum in Myanmar two weeks ago, the Philippines pressed for a freeze in "provocative actions" that could escalate tensions in the South China Sea .
But Beijing rejected the proposal, insisting that the Philippines should first drop a case it filed before an international tribunal contesting China's territorial claims and instead agree to bilateral talks.
In his TV interview on Sunday, Mr Aquino said of the vessels: "What are they doing there? What studies are they conducting? I hope (their presence) will not lead to increased tension between (the Philippines and China)."
He described the Reed Bank incident as the latest in China's "seasonal" attitude towards the Philippines.
Said Mr Aquino: "Whenever we deal with China, and with all due respect, it is like (its attitude) is seasonal.
"There is a season when China is belligerent. There is a season when it is friendly. There is a time when it goes on a charm offensive. There is a time when it doesn't."
This article was first published on August 19, 2014.
Get a copy of The Straits Times or go to straitstimes.com for more stories.