Updated

The Philippines protested Tuesday actions by the Chinese coast guard that prevented delivery of supplies to a small group of Filipino soldiers guarding a shoal in a disputed area in the South China Sea.

Chinese ships prevented two Filipino civilian vessels hired by the Philippine navy from reaching Second Thomas Shoal on Sunday, the Philippine Department of Foreign Affairs said in a statement. The shoal is called Ayungin Shoal by Manila and Ren'ai Reef by the Chinese.

"Ayungin Shoal is part of the continental shelf of the Philippines and therefore, the Philippines is entitled to exercise sovereignty rights and jurisdiction in the area without the permission of other states," the statement said.

China's actions "constitute a clear and urgent threat to the rights and interests of the Philippines" under the Law of the Sea, it added.

China's charge d'affaires was summoned and handed the protest note.

Less than a month ago, Manila also protested a Chinese water cannon attack on Filipino fisherman near another disputed shoal. No one was injured in the Jan. 27 incident at the Scarborough Shoal off the country's main island of Luzon in the north.

The Filipino troops awaiting fresh supplies are stationed on a decrepit military hospital ship that ran aground in 1999 on the shallow coral outcrop of the Second Thomas Shoal. The rusty ship has since become the symbol of the country's sovereignty over the area.

China has been demanding the removal of the ship, claiming that the area is part of Chinese territory.

Department of National Defense spokesman Peter Paul Galvez said "the Chinese coast guard ships blocked our two vessels which were en route to Ayungin to reprovision" the troops. He did not give other details.

The Chinese did not block Philippine marines and supplies to the station last June, a month after the deployment of Chinese ships to the area that also prompted diplomatic protests from Manila.

China's official Xinhua news agency on Monday quoted Chinese Foreign Ministry spokesman Qin Gang as saying that the two Philippine ships were loaded with construction materials and were driven away by Chinese coast guard vessels as they approached the shoal.

"China has indisputable sovereignty over the Nansha Islands and their adjacent waters including the Ren'ai Reef," Qin said.

China claims virtually the entire South China Sea. Nansha is the Chinese name for the Spratlys, a chain of resource-rich islands, islets and reefs claimed partly or wholly by China, Brunei, Malaysia, Philippines, Taiwan and Vietnam.