The Philippines said Sunday more than 135 Chinese vessels were "swarming" a reef off its coast, describing the boats' growing presence as "alarming".
The Chinese boats were "dispersed and scattered" within the boomerang-shaped Whitsun Reef, which the Philippines calls Julian Felipe Reef, around 320 kilometres (200 miles) west of Palawan Island, the coast guard said.
Whitsun Reef is more than 1,000 kilometres (620 miles) from the nearest major Chinese landmass of Hainan island.
The Philippines said it counted 111 "Chinese maritime militia vessels" (CMM) on November 13. When the coast guard deployed two patrol boats to the area on Saturday the number had increased to "more than 135", the coast guard said.
"No response was made to the radio challenges issued by the PCG (Philippines Coast Guard) to the CMM vessels which is now estimated to have grown to more than 135 vessels dispersed and scattered within Julian Felipe Reef," the Manila's coast guard said, describing it as an "alarming development".
Beijing claims most of the South China Sea, including waters and islands close to the shores of its neighbours, and has ignored an international tribunal decision that its assertion has no legal basis.
It deploys vessels to patrol the waters, and has built artificial islands and military installations to reinforce its stance.
The Philippines, Brunei, Malaysia, Taiwan and Vietnam have also staked claims to various islands and reefs in the sea, which is believed to have rich petroleum reserves deep beneath its waters.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
Featured Video Of The Day
8 Indians Among 9 Rescued By Navy After Oil Tanker Capsizes Off Oman
Chinese Coast Guard Rams Philippine Vessel Amid Medical Evacuation 'Top Gun' In Real Life? Chinese, American Jets 10 Feet From Each Other Philippines Accuses China Of Water Cannon Attack On Its Boats, Releases Video World's Largest Isolated Tribe Makes Rare Appearance In New Footage Relationship Timeline Of Hardik Pandya, Wife Who "Parted Ways": 5 Facts 3 Passengers Die As Chandigarh-Dibrugarh Express Derails In UP Delhi University Inviting Applications For Course In Pali/Tibetan Hegemonistic Ambitions: Tibet PM-In-Exile On China Renaming Places In India 7 Killed, 3 Injured As Taxi Falls Into Roadside Well In Maharashtra: Report Track Latest News Live on NDTV.com and get news updates from India and around the world.