BEIJING (PTI): China has deployed its second aircraft carrier 'Shandong' which was spotted patrolling waters off the Philippine coast as Manila stepped up efforts to assert its claims over a shoal in the disputed South China Sea firmly opposing Beijing's counterclaims.

Shandong, an aircraft carrier with a displacement of about 70,000 tonnes, was seen patrolling the waters off the Philippines which serves as a deterrence against "continuous Philippine provocations" on Chinese islands and reefs in the South China Sea, state-run Global Times media reported on Monday.

The aircraft carrier is likely on a scheduled exercise that could also prepare it for a potential far sea voyage into the West Pacific, it quoted Chinese experts as saying.

Shandong's deployment comes after the People's Liberation Army (PLA) deployed major surface combat ships, including large and medium destroyers as well as the main amphibious landing ship in the South China Sea as the maritime territorial conflict with Manila escalated.

Ni Lexiong, a defence professor in the Department of Political Science at Shanghai University of Political Science and Law, was quoted by the Hong Kong-based South China Morning Post as saying that the Shandong's passage was meant to be a deterrent to Manila and Washington and underline "China's determination to protect territorial sea sovereignty" amid tensions over the Second Thomas Shoal.

Chester Cabalza, president and founder of International Development and Security Cooperation, a Manila-based think-tank, said the carrier's patrol was an example of "performative politics" by Beijing that could become a frequent event.

If so, it "would mean that there is a red flag on their national security", he said, adding that "once we see massive military force, that means that Beijing is preparing for a war", the Post reported.

In the midst of tensions, a Chinese Coast Guard ship has rescued two Philippine fishermen after their fishing vessel suffered damage after an explosion on board near Huangyan Dao, widely known Scarborough Shoal in the South China Sea.

After the incident, the Philippine side expressed gratitude for the humanitarian rescue by the China Coast Guard, Global Times reported.

The China-Philippines confrontation to assert their claims in the disputed South China Sea took a violent turn last month as their naval ships collided in the first such incident after Beijing issued new rules to act against foreign vessels and detain foreigners suspected of violating regulations in the Chinese waters.

A few weeks ago, a Philippine naval ship and a Chinese vessel collided near the Second Thomas Shoal of the South China Sea claimed by Manila.

The navies and the coast guards of the two countries were having face-offs in the last few months as the Philippines, backed by the US, made a strong bid to assert its claims over the Second Thomas Shoal in the South China Sea (SCS) claimed by China.

China claims most of the South China Sea (SCS) which the Philippines, Malaysia, Vietnam, Brunei and Taiwan hotly dispute.

China alleges that the Philippines deliberately ran a naval ship aground in 1999 at the Second Thomas Shoal, which it calls Renai Jiao, and converted the damaged ship into a permanent installation manned by naval personnel.

The Philippines, backed by the US, is trying to assert its claims over the SCS based on the 2016 ruling by a tribunal of the UN Convention of Law of Seas (UNCLOS) endorsing its rights.

China, which boycotted the tribunal, however, rejected the tribunal findings and fiercely asserted its claims.

Last month, China promulgated a new law authorising its coast guard to seize foreign ships that illegally enter China's territorial waters and to detain foreign crews for up to 60 days.

The law empowers China's coast guard to fire upon foreign ships if necessary.

For its part, the US has deployed the mid-range Typhon missile systems in the Philippines as a show of strength for its backing for Manila's claims.

The Philippines has also imported India's BRAHMOS missiles.

China currently has two aircraft carriers, Liaoning, which was a refit of the Soviet-era ship, and Shandong, which is an indigenously built 2nd aircraft carrier commissioned in 2019.

China's third aircraft carrier Fujian, which is larger than the two carriers with a displacement of 80,000, is currently undergoing trials.

It is the "first fully domestically developed and constructed" aircraft carrier with an electromagnetic aircraft launch system (EMALS) similar to that of the American aircraft carrier, USS Gerald R. Ford, according to official media reports.

China's other two aircraft carriers are equipped with ski-jump take-off ramps while the Fujian features a flat-top flight deck.

China operates its indigenously built J-15 aircraft for its carriers.