As per open domain sources, satellite images show a well-guarded Pakistan’s underground facilities at Kirana
Hills, approximately 8 km southeast of the Sargodha Air Base in Punjab province are. The facility covers an area of 67.59 sq km with a perimeter of 39 km. The complete area is acquired by the Pakistan government to avoid any security infringements. The area
is well guarded and secure from various threats and hazards. The facility is well connected with road, rail and air.This facility, stores M-11 missiles, supplied by China. There are at least 10 tunnels constructed in between 2004 to 2016 by Special Works Development
(SWD), a military unit created to handle field engineering work of nuclear sites by use of Chinese tunnelling technology. The tunnels have 5-15m wide entrances. They are located at different heights above the ground level suggesting there is a huge area inside
it. The height of underground structure can be as high as, at least three-storey building. The tunnels are interconnected to avoid blockage of exits during war. Pakistan seems to have decided to focus on safeguarding the entrances since 2016. Six of the tunnel
entrances have been chosen for the special construction, designed to withstand the effects of kinetic weapons. The rest will probably be constructed in the second phase.
Pakistan has constructed numerous tunnels to store its nuclear weapons. Such underground facilities can be safeguarded through various means such as blocking their view, controlling access and detecting intrusions. Pakistan
has made these tunnels almost impenetrable. The analysis of satellite images taken from 2009 to 03 June 2017 reveals that Pakistan's special efforts to make its tunnels at Kirana Hills bomb-proof. Frantic activities in these top secret nuclear facilities is
being seen as a counter measure to latest successful firing of Indian precision cruise missile Brahmos from Sukhoi platform.