The PLA base at Sirjap, nestled amid mountains on the northern shore of Pangong Lake, is the headquarters for Chinese troops stationed around the lake

The base, built during 2021-22, has underground bunkers that can be used to store weapon systems, fuel or other supplies, according to images provided by BlackSky, a US-based firm

China’s military is digging in for the long haul in the area around Pangong Lake in eastern Ladakh, having constructed underground bunkers to store weapons and fuel and hardened shelters for armoured vehicles at a key base in the region, according to satellite images.

The People’s Liberation Army (PLA) base at Sirjap, nestled amid mountains on the northern shore of Pangong Lake, is the headquarters for Chinese troops stationed around the lake and was built in an area claimed by India and located about 5 km from the Line of Actual Control (LAC). Till the start of the standoff on the LAC in May 2020, this region was almost completely devoid of human habitation.

The base, built during 2021-22, has underground bunkers that can be used to store weapon systems, fuel or other supplies, according to images provided by BlackSky, a US-based firm capable of capturing images 15 times a day with its satellites. One image, captured on May 30, clearly shows the eight sloping entrances to a large underground bunker. Another smaller bunker, with five entrances, is located near the larger one.

Besides several large buildings for the headquarters, the base has hardened shelters or covered parking for armoured vehicles deployed in the area. These shelters are meant to protect vehicles from air strikes using precision-guided munitions, experts said.

“The base hosts an expanse of armoured vehicle storage facilities, test ranges and fuel and munitions storage buildings,” an analyst from BlackSky said on condition of anonymity. The current state of development at the base includes artillery and other defensive positions reinforced by large berms and connected by a wide-reaching network of roads and trenches that are not visible on publicly available mapping applications, the analyst said.

The base is located a little more than 120 km southeast of Galwan Valley, the site of a brutal skirmish in June 2020 that resulted in the death of 20 Indian soldiers and at least four Chinese troops.

There was no immediate response from Indian officials on the images. A former Indian Army commander who served in the region around Pangong Lake, said on condition of anonymity that China’s increased construction of underground facilities made perfect military sense.

“In today’s battlefield, everything can be pinpointed using satellites or aerial surveillance platforms. We have no such underground shelters on our side. Tunnelling is the only way out to create better defences,” he said.

“Without underground shelters, weapons and stores are sitting ducks for air strikes with precision-guided munitions. The Chinese are pioneers in tunnelling activities and no hi-tech is required for these structures, just civil engineering skills and funds. Otherwise, we have to invest in more air defence equipment,” he added.

People familiar with the matter said on condition of anonymity that India has built various roads, bridges, tunnels, airfields and helipads in its border areas for military mobility and logistics support since the standoff began in 2020.

India’s infrastructure development has focussed on better living conditions and improved facilities for soldiers, and the protection of weapons and equipment in forward areas. This border infrastructure push has been propelled by increased spending and speedy execution of strategic projects to support military operations.

During 2023-24, the Border Roads Organisation (BRO) completed 125 infrastructure projects worth ₹3,611 crore, including the Sela tunnel in Arunachal Pradesh.

The developments at Pangong Lake have come at a time when new images also suggest heightened activity by the Chinese military at Shigatse air base, a dual-use high-altitude airport in the Tibet Autonomous Region’s second largest city, and at the disputed Doklam tri-junction, the site of a 73-day standoff between Indian and Chinese troops in 2017.

While satellite images from earlier this year showed about half a dozen Chengdu J-20s, China’s most advanced stealth combat jet, at the Shigatse base, BlackSky’s image from May 30 showed six J-20 jets parked adjacent to eight Chengdu J-10 multi-role combat jets on the central apron.

The base at Shigatse is located about 300 km from the Indian Air Force’s (IAF) Hasimara base in West Bengal, which houses a squadron of Rafale combat jets. Experts believe China’s deployment of the J-20s is aimed at countering the Rafales, among the most advanced aircraft of the IAF.

While some J-20s have been deployed in Xinjiang, most of these jets were stationed in China’s coastal and inland provinces and their deployment in Tibet marks a shift, the experts said. A more recent satellite image from June 30 revealed at least two J-10 jets on the central apron at the Shigatse air base.

On the Doklam plateau, the satellite images show China maintaining an elaborate network of roads connecting military infrastructure across close to the disputed border with India. A sizeable number of military vehicles were detected at a rear base and forward position in a satellite image from April.

(With Inputs From Agencies)