MELBOURNE, Australia — China is expanding an air base on the East China Sea coast, adding facilities that potentially allow it to permanently base combat aircraft closer to Taiwan and islands of which both China and Japan claim ownership.

Satellite photos taken in April show that the construction of new 24 aircraft shelters, taxiways and additional buildings are on the verge of being completed at the air base near the town of Xiapu, in China’s coastal Fujian Province.

The new aircraft shelters are built in a semi-dispersed state in six clusters of four, with two clusters built near the end of the single 1.7-mile-long runway and the rest located in one of two aircraft dispersal area which already has 15 of the 20 hardened and camouflaged aircraft shelters at the base. Each of the new shelters measures approximately 100 feet long and 60 feet wide, which is more than enough to accommodate China’s Sukhoi Su-30/35 and Shenyang J-11/15/16 Flanker family of fighter jets.

A satellite photo of Xiapu air base dated September 2017 showing the aircraft shelters being built. More recent satellite photos show these are close to completion. (Google, with annotation by Mike Yeo/Staff)

Several military buildings have also been built as part of the upgrading project, which also includes five new barracks blocks along with what retired Col. Vinayak Bhat, who previously served as a satellite imagery analyst with the Indian Army, told Defense News appear to be parking garages and testing and inspection facilities for vehicles. Land clearing is also taking place at the north eastern corner of the base complex, suggesting more facilities could yet be added.

The semi-dispersed nature of the new aircraft shelters is a departure from the normal practice at Chinese bases, whose shelters are normally built in straight lines with the housed aircraft parked side by side, and is likely to reflect the frontline nature of the air base.

The base is located just 160 miles from Taiwan’s capital Taipei and 225 miles from the Japanese-administered Senkaku Islands in the East China Sea, making it closer to the islands than the nearest Japanese combat aircraft which are based 260 miles away at Naha in Okinawa. China is also claiming ownership of the islands, which it calls the Diaoyu Islands.

The construction of the new aircraft shelters at the air base could point to China upgrading it to a fully-fledged operational air base with its own permanently assigned combat aircraft regiment or brigade. It had previously been used only as a deployment base since completion in 2012, hosting ongoing rotating detachments of approximately 12 People’s Liberation Army Air Force or PLAAF fighter jets.

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These rotations, which satellite photos show almost always include the Sukhoi Su-30 multirole fighter or Chinese-built Shenyang J-11 interceptors, are believed to be increasingly utilised to accompany PLAAF bomber and intelligence-gathering aircraft flying out to the Western Pacific via international airspace over the Miyako Straits, with data released by the Japanese Ministry of Defense showing the fighters heading to and from the direction of Xiapu.

The fighters usually follow the bombers well past the Miyako Straits before turning back, which equates to a round trip of more than 1,000 miles from Xiapu.

PLAAF bombers have also been increasingly carrying out flights circumnavigating the island of Taiwan, which China views as a rogue province and has said it will take back by force if necessary. The latest reported mission on the 11th of May saw two groups of Xian H-6K bombers circumnavigate Taiwan simultaneously from both north and south of the island, with one group flying clockwise and the other going counter-clockwise.