MANILA — The Philippines has filed a low-key diplomatic protest with China after a United States think-tank reported that Beijing appears to have installed anti-aircraft and anti-missile weapons on its man-made islands in the strategically vital South China Sea, the country’s top diplomat said yesterday.

Foreign Secretary Perfecto Yasay said a note verbale was issued after the report came out last month. “We have taken action on that,” he said, referring to a diplomatic communication that is issued in the third person and is not signed. It is less formal than a diplomatic note.

He did not say when it was issued, adding it was a matter that he did not want to discuss.

The Center for Strategic and International Studies report said that anti-aircraft guns and close-in weapons systems designed to guard against missile attack have been placed on all seven of China’s newly created islands.

Mr Yasay told CNN Philippines that Manila had responded, but did so quietly.

“I just want to assure the Filipino people that when we take action at engaging China in this dispute, we do not want to take such aggressive, provocative action that will not solve the problem,” he said. “We cannot engage China in a war.”

The US think-tank reported last month citing new satellite imagery that it had been tracking construction of hexagonal structures on Fiery Cross, Mischief and Subi reefs in the disputed Spratly Islands since June and July. China has already built military-length airstrips on these islands.

It said covers had been installed on the towers at Fiery Cross, but the size of platforms on these and the covers suggested they concealed defence systems similar to those at the smaller reefs.

China’s Defence Ministry responded in a statement on its microblog saying that it was “legitimate and lawful” for it to place defensive military installations on islands where it said Beijing had “indisputable sovereignty”. AGENCIES