China's carrier Liaoning is seen passing through the Basilan Strait off the southern Philippines

The Chinese aircraft carrier Liaoning and its escorts were seen passing through the Basilan Strait, the narrow channel between Basilan island and Zamboanga City on the western tip of Mindanao in the southern Philippines, USNI News reported on 23 October. The sighting puts the People's Liberation Army Navy carrier group far to the south of the track it followed past Taiwan and Japan's southern islands earlier this month.

According to USNI News, the group consists of the Liaoning, hull number 16, the large Type 055 warships Anshan and Wuxi, which it described as cruisers, and a destroyer with hull number 123. Defense News, reporting from New Taipei City on the same day, said local media in East Asia had placed the carrier group on a course for the South China Sea near the Philippines, sailing with two large destroyers and a guided-missile destroyer.

The first public reports of the position came from social media. Taiwan's United Daily News said a Philippine military-interest Facebook page had posted a photo of what it said was probably the Liaoning, with a community member saying the picture was taken while passing between Zamboanga City and Basilan. The newspaper said a Facebook account of Zamboanga City also posted that the Chinese carrier had been spotted in the Basilan Strait. A Chinese military blogger on Weibo separately claimed that the carrier had been seen in the Sulu Sea west of Mindanao.

No government has publicly confirmed the sighting. United Daily News said the Armed Forces of the Philippines had issued no official information on the Liaoning, and TaiwanDefence has not seen a statement from the Philippine military or from China on the carrier's current position. The USNI News account and the social media posts agree on the location, but the exact time of the passage has not been officially established.

The report fills a gap of more than a week. Japan's Joint Staff last reported the Liaoning about 250 kilometres south of Ishigaki Island in mid-October, after which it headed for the South China Sea and its movements went unreported, according to United Daily News. The newspaper said the new position fits that southward course, with the group apparently passing Palawan into the Sulu Sea before reaching the Basilan Strait area.

The voyage began on 14 October, when the carrier led a task group into the western Pacific. The Chinese navy, through the state news agency Xinhua, described the deployment as part of an annual routine training plan meant to test and improve combat readiness. That is China's own account of the purpose and has not been independently verified.

During the earlier leg, Japan's defence ministry said it saw fighter jets taking off and landing on the Liaoning about 250 kilometres south of Ishigaki, according to Defense News. Colin Karotam of the Australian Strategic Policy Institute told the outlet that the group launched and recovered aircraft inside Japan's exclusive economic zone, which he called uncommon. The deployment also started shortly before the US-Japan Keen Sword 27 exercise opened on 19 October, an exercise in which the Philippines is taking part.

Analysts quoted by Defense News saw the voyage as part of a routine. Carl Thayer of the University of New South Wales described it as an established and evolving pattern of far-seas training. Collin Koh of Nanyang Technological University said the older carrier probably helps validate technology for the newer Shandong and Fujian, while Alexander Huang of the Council of Strategic and Wargaming Studies in Taipei said the Liaoning would not be China's front-line reaction force in a contingency.

Taiwan's defence ministry said in mid-October that it was watching for possible large-scale Chinese drills linked to the carrier's movements, Defense News reported. A Chinese carrier group operating off Mindanao shows the PLA Navy taking its training deployments deep into the southern Philippine archipelago, well beyond the waters around Taiwan and Japan where its carriers are usually tracked.