Photo/IllutrationThe Philippine Navy ship BRP Gregorio del Pilar is seen on Aug. 29 after it ran aground during a routine patrol in the vicinity of Half Moon Shoal, which is called Hasa Hasa in the Philippines, off the disputed Spratlys Group of islands in the South China Sea. (Armed Forces of the Philippines via AP, file photo)

MANILA--The Philippine Navy extricated one of its largest warships from the shoal where it ran aground last week near a hotly disputed region in the South China Sea.

Two Philippine security officials said Tuesday that tugboats were used to pull the BRP Gregorio del Pilar from the shallow fringes of Half Moon Shoal, which the Philippines calls Hasa Hasa, before midnight.

The frigate, which was being towed back to a Philippine port, ran aground during a routine patrol Wednesday night, damaging some of its propellers. Its more than 100 crewmen were unhurt.

The barren shoal is on the eastern edge of the disputed Spratly archipelago, where tensions have run high in recent years after China built seven disputed reefs into man-made islands and reportedly installed missile defense systems.

Philippine defense officials notified their Chinese counterparts after the accidental grounding of the Philippine Navy frigate at the shoal, which Beijing claims, to avoid any misunderstanding, said the two Philippine officials, who spoke to The Associated Press on condition of anonymity because they were not authorized to discuss the issue publicly.

Defense Secretary Delfin Lorenzana said last week that China offered to help but that the Philippines would handle it.

A Chinese frigate ran aground on the shoal in 2012 and was pulled away by Chinese military ships.

Half Moon Shoal lies about 110 kilometers from the southern tip of the western Philippine island of Palawan and south of the disputed Second Thomas Shoal, where a Philippine navy transport ship was intentionally grounded in 1999 and has since served as a Philippine military outpost.

China has repeatedly demanded the now-rusty BRP Sierra Madre be removed from Second Thomas Shoal, which is claimed by the Philippines and China.

A military report seen by the AP said the propellers of the BRP Gregorio del Pilar were damaged by the grounding. The crew reported, however, that the frigate was not taking in water.

At least four Philippine Navy and Coast Guard ships were deployed to secure the BRP Gregorio del Pilar and provide food and other supplies to its sailors. Tugboats were hired to extricate the ship, military spokesman Col. Noel Detoyato said.

The frigate is one of three former U.S. Coast Guard cutters acquired by the Philippine military and are the Philippines' largest warships.

The United States and Asian governments which have claims in the disputed sea, including the Philippines, have raised alarms over China's island building and militarization of the strategic territory.

The Philippines has been one of the most vocal critics of China's assertive moves in the disputed waters. In 2016, it largely won a complaint it lodged before an international tribunal, which invalidated Beijing's sweeping territorial claims in the South China Sea.

Philippine President Rodrigo Duterte, however, took steps to revive once-frosty ties with China after he took office in 2016 as he sought infrastructure funding and more trade and investment from Beijing.