Hong Kong ( CNN ) -- The Philippines said Wednesday that its largest naval vessel is engaged in a standoff with two Chinese maritime surveillance ships in a remote lagoon in the South China Sea . The Philippine Department of Foreign Affairs said the country 's navy had sent the BRP Gregorio del Pilar , a 378-foot cutter , to the area of Scarborough Shoal on Sunday after surveillance aircraft spotted eight Chinese fishing boats anchored inside the lagoon . China and the Philippines both claim that Scarborough Shoal , about 200 kilometers west of the Philippine mainland , is `` an integral part '' of their territory . A boarding team from the Gregorio del Pilar went to inspect the Chinese fishing boats Tuesday morning and found `` large amounts of illegally collected corals , giant clams and live sharks '' inside one of the boats , the Department of Foreign Affairs said in a statement . Later Tuesday , the Gregorio del Pilar reported that the two Chinese surveillance ships had arrived and taken up a position at the mouth of the lagoon , blocking the way to the fishing boats and `` preventing the arrest '' of the fishermen . The situation remained the same Wednesday morning , the Philippine statement said . The Philippine foreign minister , Albert Del Rosario , is seeking a `` diplomatic solution '' to the situation with China , the statement said . The Chinese Embassy in Manila has complained to the Philippine authorities about `` the harassment of Chinese fishermen , '' China 's official news agency reported Wednesday . China has `` urged the Philippine side to stop immediately their illegal activities and leave the area , '' Xinhua reported , saying that the fishermen were taking shelter in the lagoon `` due to harsh weather conditions . '' The embassy is `` still engaged in discussions with the Philippine Department of Foreign Affairs to seek a solution '' and maintain peace and stability in the South China Sea , Xinhua said . The South China Sea -- a 1.3 million square mile patch of the Pacific Ocean bracketed by China and several Southeast Asian nations -- is dotted with hundreds of largely uninhabited islands and coral atolls that are home to some of the world 's most diverse marine life . Also under its waves lie potentially huge reserves of natural gas and oil . That prospect has peppered the sea with competing claims from China , Vietnam , the Philippines , Malaysia , Brunei and Taiwan . It has also resulted in frequent small-scale clashes . Last year , a spate of incidents took place between Chinese and Vietnamese vessels . CNN 's Jethro Mullen and Brian Walker contributed to this report .
The US sends a naval vessel to a lagoon in the South China Sea . It claims Chinese fishing boats in the lagoon had illegally collected corals and fish . Chinese surveillance ships arrive at the lagoon and block the entry to the lagoon . Both countries claim the lagoon is ` ` an integral part '' of their territory .