New Delhi: Pakistan activated spies and sleeper cells inside India during Operation Sindoor in an effort to locate the Indian Air Force’s S-400 air-defence systems, Air Marshal Jeetendra Mishra (retired) has said. Mishra, who commanded Western Air Command during the May 2025 hostilities, said the long-range systems had become a major threat to Pakistani fighter operations.
Mishra said Pakistani fighter aircraft could not approach within roughly 200 kilometres of the Indian border because of the threat posed by the S-400.
He also claimed Pakistan used several intelligence-gathering methods to try to identify where the systems had been positioned, including spies and sleeper cells operating inside India.
Pakistan was also receiving satellite assistance from other countries, AM Mishra said, without identifying them. His claim about foreign satellite support could not be independently verified.
Pakistan activated sleeper cells to locate S-400s
Mishra described the S-400 as Pakistan’s “biggest threat” during the conflict and said Pakistani intelligence used multiple means to try to identify its location. He said spies and sleeper cells inside India were activated as part of that effort.
The claims about sleeper cells are based on Mishra’s account. Indian intelligence and investigating agencies have not publicly identified individual networks allegedly tasked with locating the S-400 systems during Operation Sindoor.
Mishra was the air officer commanding in chief of Western Air Command during the conflict. He assumed command in January 2025.
Why the S-400 was a key target
The S-400 is a Russian-origin long-range surface-to-air missile system designed to detect, track and engage aircraft and other aerial threats over a large area.
India signed a contract with Russia on October 5, 2018, for five squadrons of the S-400 system. The defence ministry has described the platform as capable of providing continuous air-defence coverage over a large area and protecting vulnerable areas and critical points.
During Operation Sindoor, the S-400 formed part of India’s layered air-defence network alongside other surface-to-air missile systems, radars, counter-drone equipment and electronic-warfare assets.
Mishra said its reach restricted the freedom of Pakistani fighter aircraft to operate close to the border.
The Indian Air Force has previously made similar claims about the system’s effect during the conflict. In August 2025, the then IAF chief, Air Chief Marshal AP Singh, said the S-400’s range had kept Pakistani aircraft at a distance and restricted their ability to effectively employ some long-range weapons.
The Indian government has also highlighted the system’s role during Operation Sindoor. Following the conflict, the prime minister, Narendra Modi, said systems including the S-400 had strengthened India’s air defence shield and helped protect airbases and other critical defence infrastructure during Pakistani attacks.
S-400 formed part of layered air defence
Operation Sindoor began on May 7, 2025, when India struck nine terrorist infrastructure sites in Pakistan and POK following the April 22 Pahalgam terror attack in which 25 Indian tourists and one Nepali national were killed.
Pakistan subsequently launched drones, missiles, rockets and other long-range weapons against Indian military and civilian targets.
The defence ministry’s 2025 year-end review said Indian air-defence, counter-drone and electronic systems thwarted Pakistani attacks involving missiles, drones, rockets and other long-range weapons on May 10, preventing damage to vital military assets.
The Indian Air Force subsequently struck Pakistani airbases, command-and-control facilities and other military infrastructure before both sides agreed to stop military operations.
Official Indian accounts have described the S-400 as one element of the wider integrated air-defence network rather than the only system involved in countering Pakistani aerial attacks.