MELBOURNE, Australia — China has taken delivery of the Sukhoi Su-35 "Flanker-E" fighter jet from Russia, according to Chinese state media.

The Chinese military confirmed that it took delivery of four Su-35s in late December, the English-language China Daily newspaper reported without providing further details. 

However, an Ilyushin Il-76 transport aircraft belonging to Russian charter company Volga-Dnepr was noted on the live flight-tracking website Flightradar24. The aircraft was flying from Komsomolsk-on-Amur, where the Su-35 is built by the Komsomolsk-on-Amur Aircraft Production Association (KnAAPO), to Cangzhou-Cangxian Airbase in China’s Hebei Province before carrying on to Suixi Airbase in Guangdong Province on December 25.

Cangzhou-Cangxian is the home of the Flight Test and Training Centre (FTTC), the People’s Liberation Army Air Force (PLAAF) unit responsible for developing flying procedures, combat tactics and training programs for new aircraft types. Suixi is the nearest PLAAF base to the disputed islands of the South China Sea.

It is not known if the Il-76 was accompanying the Su-35s, or operated as a separate flight carrying support equipment and spares for the newly-delivered fighters. China has also not released any official photos of its Su-35s, although grainy images purporting to be the PLAAF Su-35s have been published on Chinese social media.

China confirmed in November 2015 that it signed a $2 billion contract with Russia for the acquisition of 24 Su-35s, following more than five years of on-again, off-again negotiations for the aircraft.

Andreas Rupprecht, author of three books on Chinese military aviation and industry, told Defense News that one of the reasons China is keen on acquiring the Su-35 is to access modern Russian engine technology in the form of the Saturn AL-41F1S (117S) afterburning turbofan engine and the associated thrust-vectoring capability of the super-maneuverable Su-35.

China has been trying to develop its own indigenous fighter jet engine for several years, but the program has been dogged by technical problems. China’s stealthy Chengdu J-20, single-engine Chengdu J-10 and Shenyang J-15 carrierborne fighters are still powered by Russia’s Saturn AL-31 engine.

Rupprecht also noted that if the PLAAF's Su-35s are indeed based at Suixi, it would also raise the possibility that they could "act as a long range fighter escorts for the (PLAAF's) H-6K bombers around the South China Sea or even facing Japan."

The Su-35 has the capability to refuel inflight from China's small fleet of Ilyushin Il-78 tankers acquired from Ukraine. That would give aircraft improved endurance for bomber escort and combat air patrol missions over the South China Sea compared to the Shenyang J-11Bs of the PLA Navy, which currently have primary responsibility over the area. The J-11Bs

are Chinese-built Su-27 Flankers incorporating Chinese avionics, engines and weapons.

Mike Yeo is the Asia correspondent for Defense News.

More In Air Warfare