(Bloomberg) -- China’s Coast Guard installed a floating barrier in the southeast portion of Scarborough Shoal in the South China Sea that’s preventing access for Filipino fishing vessels, according to the Philippines.

Manila’s Coast Guard and its Bureau of Fisheries and Aquatic Resources “strongly condemn” China’s move which was discovered by personnel of both agencies when they conducted a routine maritime patrol in the vicinity of the shoal on Friday, Philippine Coast Guard spokesman Jay Tarriela said in a post on X, formerly Twitter, on Sunday.

The floating barrier which measures about 300 meters (328 yards) was installed by three inflatable boats of the Chinese Coast Guard and a service boat of the Chinese maritime militia, according to the post. It cited Filipino fishermen who said the Chinese Coast Guard vessels “usually install floating barriers” when they see a number of Philippine fishing boats in the area.

Calls to the office of Chinese foreign ministry’s spokesperson were unanswered outside of regular business hours.

Four Chinese Coast Guard vessels “initiated a series of 15 radio challenges in an attempt to drive away” the Philippine fisheries bureau’s vessel and more than 50 fishing boats, Tarriela said.

China’s Coast Guard crew alleged the presence of the Philippine boats “violated international law and the domestic laws of China,” he said. After realizing the presence of media personnel on board the fisheries bureau’s ship, the Chinese vessels “maintained a safe distance and moved away,” he added.

Manila has been releasing videos and images of persistent confrontations of its vessels with Chinese ships in a bid to pressure Beijing to stop what it says are the latter’s “aggressive” acts in the disputed sea.

Last week, the Philippine government said it may file a complaint against China before an international court for damages in its coral reef in the South China Sea. Beijing said Manila’s claims are unfounded and it should tow away a World War II-era ship in Second Thomas Shoal to prevent it from discharging polluted water.

China’s statement about the ship “will only heighten the mistrust by the Filipino people and the rest of the world of the Chinese government,” Philippine Defense Secretary Gilberto Teodoro Jr. said in a statement on Saturday. 

--With assistance from Jing Jin.

©2023 Bloomberg L.P.