FOREIGN Affairs Secretary Teodoro L. Locsin, Jr. yesterday ordered the filing of a diplomatic protest against China over the presence of its ships near Second Thomas Shoal in the South China Sea.

“I’m in Moscow. Do I have to fly home to file the diplomatic protest myself?” Mr. Locsin said in a social media post past midnight on Wednesday. “File now.”

Mr. Locsin was in Russia to accompany President Rodrigo R. Duterte on his second visit there.

The Philippine military has reported the unannounced entry of Chinese vessels near the shoal to the Foreign Affairs department for appropriate diplomatic action, Armed Forces Chief of Staff Noel S. Clement told reporters at the Senate on Tuesday.

He said the agency would have to decide whether there was a violation.

Mr. Clement said the report was made through the task force on the West Philippine Sea, Manila’s name for areas of the South China Sea within its exclusive economic zone.

Mr. Locsin earlier threatened to fire off diplomatic protests against China’s incursions in the South China Sea.

The Philippine has protested the presence of Chinese warships and survey ships within its exclusive economic zone.

Protests were also filed over the presence of Chinese vessels near Thitu island in the South China Sea.

Last week, Washington-based think tank Center For Strategic and International Studies, through a brief released by the Asia Maritime Transparency Initiative, said China was sending larger but lightly armed coast guard vessels around Ayungin Shoal, Luconia shoals in the Spratlys and Panatag Shoal up north.

Ayungin is the Philippine name for Second Thomas Shoal and it calls the Scarborough Shoal Panatag.

More heavily armed vessels carrying 76 mm cannons have also patrolled the region but have been more frequently seen since last year in larger deployments such as those near the Philippine-occupied Thitu or Pagasa Island.

These large Chinese coast guard ships numbering as high as 14 have been broadcasting their presence using transponders while patrolling around these shoals. Other Chinese vessels deployed in the region but doing patrols in other areas have their transponders turned off, according to Asia Maritime Transparency.

Manila earlier criticized China after a coast guard ship in May allegedly blocked three Philippine vessels trying to bring supplies to a navy ship that was deliberately run aground at the Second Thomas Shoal in 1999.

The Chinese Coast Guard ship had blocked the Philippine ships on a resupply mission in May to BRP Sierra Madre at the South China Sea shoal, according to the Defense department.

Last month, the Armed Forces said at least five Chinese warships had passed through the Sibutu Strait in Tawi-Tawi province in southern Philippines without notice.

The Palace has said that authorities would “shoo away” unauthorized foreign vessels including Chinese warships that pass through Philippine waters and use military force if necessary.

In his fifth visit to China, the President invoked a 2016 ruling by an international arbitration panel in the Hague that rebuffed Chinese claims over parts of the South China Sea.

The United Nations tribunal in July 2016 ruled China’s efforts to assert control over the South China Sea exceeded the law, rejecting its shared claims with Taiwan to more than 80% of the main waterway.

China rejected the decision of the international court, which has failed to halt its island-building activities in areas also claimed by the Philippines, Vietnam, Brunei, Malaysia and Taiwan. — Charmaine A. Tadalan