(Updated)
A Russian diesel-electric attack submarine has been monitored in Occidental Mindoro last week before it surfaced in the West Philippine Sea (WPS), the Armed Forces of the Philippines (AFP) and Philippine Coast Guard (PCG) confirmed Monday, Dec. 2.
“I would just like to confirm the report of the Philippine Navy (PN) that there is a presence of a Russian submarine that we monitored in Occidental Mindoro,” said Commodore Jay Tarriela, PCG spokesperson for WPS.
"[T]he Russian submarine passed through our exclusive economic zone,” Tarriela added.
The AFP identified the underwater vessel as Russian Pacific Fleet's "Ufa 490", which was sighted 80 nautical miles west of Cape Calavite, Occidental Mindoro last Nov. 28.
The Philippine Navy (PN) immediately deployed assets to monitor and address the situation to ensure the security of Philippine waters, according to Rear Adm. Roy Vincent Trinidad, PN spokesperson for WPS.
The sighting came in the wake of Russian Pacific Fleet’s announcement that Ufa conducted a passage exercise (PASSEX) with Malaysian Navy vessels in the South China Sea on Nov. 25.
The Russian News Agency reported that Ufa, built at the Admiralty Shipyard in St. Petersburg in Russia’s northwest, was “making an inter-fleet transit from the Baltic Sea to the Pacific Fleet through the southern maritime route.”
Trinidad said that the PN's BRP Jose Rizal (FF150) established radio communications with the Russian submarine, which confirmed its identity, crew complacent, and navigational intent. Four different aircraft were also sent to monitor the submarine.
"The Russian vessel stated it was awaiting improved weather conditions before proceeding to Vladivostok, Russia," Trinidad explained.
"Philippine naval forces, including FF150, escorted and monitored operations to ensure the submarine's compliance with maritime regulations within the Philippine exclusive economic zone," he said.
Ufa was accepted for service with the Russian Navy on November 16, 2022, and is the fourth in a series of six Project 636.3 submarines being built for Russia’s Pacific Fleet, according to the Russian News Agency.
“The submarines of this Project optimally combine acoustic stealth, the target detection range and powerful torpedo and missile armament. They carry the Kalibr high-precision missile system as their basic strike weapon,” the news agency reported.
Nonetheless, the AFP emphasized its commitment to safeguard the country's maritime sovereignty while maintaining professionalism in interactions with foreign naval vessels.
"Our operations remain consistent with international maritime laws and demonstrate our dedication to regional peace and cooperation," Trinidad said.
While the detection was rather unusual, Trinidad said this is not a cause for concern.
"It's the first time that we detected something like that, and it's the first time that we were able to repond and track. We were surprised but we were able to establish communication. The exchange of information was friendly so it was not alarming," he noted.
The official also said that the passage of the Russian submarine was not illegal under the United Nations Convention on the Law of the Sea (UNCLOS).
"It is not illegal because it is authorized under UNCLOS. It can pass through our exclusive economic zone under freedom of navigation. Nothing aggressive was done by the submarine. As of Dec. 1, it is already in the northern part of our country on it way out," he said.