China’s air force has stepped up combat training exercises involving its J-20 stealth fighters , according to state media, as tensions in the region continue to mount. Footage from a drill aired on official broadcaster CCTV recently showed two of the warplanes firing dozens of decoy flares, which are typically used during dogfights. The flares burn at high temperatures and are used to counter heat-seeking missiles fired by the adversary that target aircraft engines. Stealth fighters like the J-20 have a cross-section design to reduce visibility and a radar-absorbent coating that makes it difficult for the enemy to detect them and harder for radar-guided missiles to target them. But in an encounter with enemy aircraft within visual range, or if other types of missiles are being fired, decoy or countermeasure flares are needed, according to military commentator Song Zhongping. “This training [using decoy flares] is essential for actual combat situations,” said Song, who is based in Hong Kong. “It’s a very useful tactic for a close-up dogfight between fighter jets, or if they’ve been targeted by a surface-to-air missile from a ground air-defence system.” The J-20 is China’s most advanced, and the only fifth-generation, stealth fighter in service and has featured in the People’s Liberation Army’s recent shows of military might. The drills involving the warplane were highlighted on state television amid escalating tensions in the South China Sea , across the Taiwan Strait , and on its border with India , and it comes as President Xi Jinping has called on the military to focus on “preparing to go to war” . The Chinese air force has ramped up activity near Taiwan recently , and a J-20 was spotted flying low over Quzhou in Zhejiang province last month – just 20 minutes away from the self-ruled island. That was seen as Beijing sending a warning to Taiwan, which it regards as part of its territory, to be brought under mainland control by force if necessary. If a conflict did erupt across the straight, the J-20 would be up against Taiwan’s advanced F-16 fighter jets. The island has put in an US$8 billion order for 66 additional upgraded F-16V jets from Lockheed Martin, which will take its fleet to more than 200 by 2026. Meanwhile, a border stand-off with India continues in the Himalayas, and two J-20s were seen at Hotan airbase in China’s far western Xinjiang – close to the disputed region – in August. India reportedly deployed five new Dassault Rafale fighter jets to nearby Ladakh. The J-20, a single-seat twin-engine stealth fighter, entered service in 2017 but has been dogged by engine development problems. The PLA Air Force has not revealed how many J-20s it has, but the number has been estimated to be at least 50.