‘We call on the Chinese to stop this incursion and immediately recall these boats violating our maritime rights and encroaching into our sovereign territory,’ Philippines Defence Minister Delfin Lorenzana said.

The Philippines on Sunday urged China to recall more than 200 Chinese boats it said had been spotted at a reef in the South China Sea, saying the presence of the vessels violated its maritime rights as it claims ownership of the area.

In an unusual announcement published by the Presidential Communications Operations Office (PCOO) on its Facebook page, the National Task Force on the West Philippine Sea said ships have “massed” at the Julian Felipe Reef, the official Philippine name for Whitsun Reef, Manila Times reported. Julian Felipe Reef is a large boomerang-shaped shallow coral reef 175 nautical miles west of Bataraza, Palawan, and northeast of Pagkakaisa banks and reefs or the Union Reefs. The reef is claimed by China and the Philippines both.

Authorities said the Philippines coast guard had reported that about 220 vessels, believed to be manned by Chinese maritime militia personnel, were seen moored at the Whitsun Reef, which Manila calls the Julian Felipe Reef, on 7 March.

“We call on the Chinese to stop this incursion and immediately recall these boats violating our maritime rights and encroaching into our sovereign territory,” Defence Minister Delfin Lorenzana said.

The Philippine military had conducted air and maritime patrols in the South China Sea to further validate the report, spokesman Marine Major General Edgard Arevalo said, but did not say when.

The military had submitted its findings to other government agencies, and they would be used as basis for taking “appropriate actions not limited to filing diplomatic protests”, he said in a statement, without elaborating.

“Despite clear weather at the time, the Chinese vessels massed at the reef showed no actual fishing activities and had their full white lights turned on during night time,” the task force said in a statement issued Saturday night.

It said it considered the presence of vessels as a “concern” because of the possibility of overfishing and destruction of the marine environment in the area. The task force also raised “risks to the safety of navigation”.

Last month, the Philippines threatened to order its navy to shoot back at any possible Chinese aggression after China passed a coast guard law allowing it to shoot at vessels in territories claimed by the communist nation. China claims sovereignty over almost the entire South China Sea and has overlapping territorial claims with Brunei, Malaysia, the Philippines, Vietnam and Taiwan.

China has been increasing its maritime activities in both the South China Sea and the East China Sea over the past few months, partly in response to Beijing’s concerns over the increasing US military presence in the region because of escalating Sino-US tensions.

Beijing’s rising assertiveness against counter claimants in the East and South Sea has resulted in unprecedented agreement across the Indo-Pacific.