According to The Hindu, India’s MiG-21s were the first to intercept the intruding Pakistani fighter jets because the Su-30s were deployed further behind the border due to a lack of hardened aircraft shelters at bases near the front line.
VargaA [CC BY-SA 4.0], via Wikimedia Commons
Anonymous officials say the shelters are being built but it will take three to four years to complete as the project was only approved in 2017 due to bureaucratic delays.