Both India and China have deployed their most advanced fighter jets to airbases near their disputed Himalayan border, according to recent satellite imagery and local reports.

Commercial satellite imagery shows two Chinese J-20 stealth fighters have recently appeared at the Hotan airbase in China’s far-western Xinjiang region, Forbes reported on August 17. “It’s not clear whether there are more J-20s out west [in Xinjiang] than just two that are visible in the satellite photo. The Chinese air force possesses only around 40 J-20s,” the report noted.

The Hotan airbase is located just 200 miles from India’s northern Ladakh region. Ladakh’s Galwan Valley was the site of India and China’s deadliest border conflict in over 45 years on June 15, when a skirmish between the neighbors’ border regiments killed 20 Indian soldiers and an estimated 40 Chinese troops. Since the deadly clash, India and China have remained engaged in an ongoing standoff along their shared boundary in the Himalayas, with both sides increasing their military presence along the unmarked border.

On July 29, India sent five new Dassault Rafale fighter jets to Ladakh. Last week, the Hindustan Times reported that the jets had recently been “practicing night flying in the mountainous terrain” of India’s nearby Himachal Pradesh state, which borders Ladakh to the south. The local Indian squadron ordered the fighter jets’ pilots to practice flying in adverse conditions so that they “will be ready if the situation deteriorates on the … Line of Actual Control (LAC, India’s official name for the India-China border) in the Ladakh sector,” the newspaper wrote, quoting “people familiar with the matter.”

China’s Hotan airbase, where it recently deployed two new J-20 stealth fighters, is located at 4,600 feet above sea level. In the Himalayas, some mountains rise over 26,247 feet, making an aircraft’s flight ceiling — the highest altitude at which a plane can fly — an important consideration for any mountain squadrons. India’s new Dassault Rafales deployed to Ladakh have a flight ceiling of about 52,493 feet, while the Chinese J-20s at nearby Hotan Airbase can fly at over 65,616 feet, the South China Morning Post reports.