New Delhi, Aug 30: In a significant development, the Russian side has submitted a detailed proposal to the Defence Ministry in response to the Indian tender for acquiring five more squadrons of the S-400 Sudarshan long-range air defence systems for the Indian Air Force.

The S-400 played a major role in India's success during Operation Sindoor, as it was responsible for taking out a large number of Pakistani surveillance and fighter aircraft while deterring others from even flying within 200 km of the Indian border.

"The Russian response to the Indian tender has been received, and it is being processed at the moment. The project is estimated to cost over Rs 50,000 crore," Defence sources told ANI when asked about the status of the project.

The Indian side has already received four of the five S-400 squadrons ordered under the first contract between the two countries in 2018. The sources said the last squadron is now expected to be delivered by November this year.

The deliveries of the missile systems under the new contract being processed are likely to start about three years after the signing of the deal.

India had cleared plans to procure five additional squadrons of the Russian S-400 air defence missile system in March this year, soon after Operation Sindoor concluded.

The additional units are expected to be deployed along both the eastern and western fronts to strengthen India's layered air defence network.

The S-400 played a crucial role in thwarting all Pakistani attempts to hit targets in India during Operation Sindoor.

Western Air Command chief Air Marshal Jeetendra Mishra, in a recent podcast with ANI, said the S-400 achieved what was possibly the longest-ever recorded surface-to-air missile kill when it destroyed a Pakistan Air Force surveillance aircraft at a range of 314 kilometres.

He also stated that the missile system was responsible for taking out many Pakistani fighter aircraft, including the J-10s supplied to Islamabad by China.

Air Marshal Jeetendra Mishra also revealed that Pakistan deployed spies and activated sleeper cells in India to locate the S-400 air defence systems during Operation Sindoor.

India is also buying over 280 missiles for the S-400 air defence systems to bolster the numbers in its arsenal.

The Indian side is also developing its own version of the long-range air defence systems under Project Kusha, where it tasted initial success recently when it took out a simulated target at around 140 km.

India also has plans to deploy a mega air shield across the length and breadth of the country under Mission Sudarshan Chakra, for which major systems are being acquired by different agencies. (ANI)