The military said the structures were spotted during maritime patrols conducted on Tuesday, but it did not give the precise location of the structures or more details as to their construction, saying only their presence violated international law.
“These structures are illegal,” military chief-of-staff Lt. Gen. Cirilito Sobejana said in a statement.
“The Laws of the Sea gives the Philippines indisputable and exclusive rights over the area. These constructions and other activities, economic or otherwise, are prejudicial to peace, good order, and security of our territorial waters,” Sobejana said.
“We have already updated our higher civilian authorities such as the Department of Foreign Affairs and Department of National Defense about these offenses to our sovereignty,” the general said.
Among the features in the Union Banks, which the Philippines calls the Pagkakaisa Banks is Whitsun Reef, called Julian Felipe Reef by Manila.
The reef, which is part of the Spratly Islands archipelago, is claimed by both the Philippines and China. The Philippines maintains that it falls inside the country’s exclusive economic zone. A 2016 ruling by a United Nations tribunal dismissed China’s claim to virtually all of the South China Sea, although Beijing has refused to recognize the decision.
China has built and military fortified man-made islands in the Spraty chain, including Mischief Reef in the vicinity of Whitsun Reef.
Whitsun Reef protects a lagoon where the Philippines says more than 200 fishing boats under the direction of the Chinese maritime militia have massed over the past several weeks.
Manila has protested the presence of the boats with the Chinese government as a violation of its sovereignty and called for them to leave the area.
“Due to maritime situation, some fishing boats have been taking shelter from the wind near Niu’e Jiao, which is quite normal. We hope relevant sides can view this in a rational light,” Foreign Ministry spokesperson Hua Chunying said last week.
On Wednesday, the Philippine government released images and video of the Chinese vessels, which it says were made on March 27.
Philippine government images going back to March 7 show the Chinese boats in the lagoon.