troops. However, because of the nature of the terrain, division and corps operations could not be mounted; subsequent fighting was conducted mostly at the brigade or battalion level. In effect, two divisions of the Indian Army, numbering 20,000, plus several thousand from the Paramilitary forces of India and the air force were deployed in the conflict zone. The total number of Indian soldiers that were involved in the military operation on the Kargil-Drass sector was thus close to 30,000. The number of infiltrators, including those providing logistical backup, has been put at approximately 5,000 at the height of the conflict. This figure includes troops from Pakistan-administered Kashmir who provided additional artillery support. The Indian Air Force launched Operation Safed Sagar in support of the mobilisation of Indian land forces on 26 May. The Indian government cleared limited use of Air Power only on 25 May, for fear of undesirable escalation, with the fiat that IAF fighter jets were not to cross the LOC under any circumstance. This was the first time any air war was fought at such high altitudes globally, with targets at altitudes between above sea level. The rarified air at these altitudes affected ballistic trajectories of air to ground weapons, such as rockets, dumb and laser guided bombs. There was no opposition at all by the Pakistani Air Force, leaving the IAF free to carry out its attacks with impunity. The total air dominance of the IAF gave the aircrew enough time to modify aiming indices and firing techniques, increasing its effectiveness during the high altitude war. Poor weather conditions and range limitations intermittently affected bomb loads and the number of airstrips that could be used, except for the Mirage 2000 fleet, which commenced operations on 30 May. Naval action The Indian Navy also prepared to blockade the Pakistani ports (primarily the Karachi port) to cut off supply routes under Operation Talwar. The Indian Navy's western and eastern fleets joined in the North Arabian Sea and began aggressive patrols and threatened to cut Pakistan's sea trade. This exploited Pakistan's dependence on sea-based oil and trade flows. Later, then–Prime Minister of Pakistan Nawaz Sharif disclosed that Pakistan was left with just six days of fuel to sustain itself if a full-scale war had broken out. India attacks Pakistani positions The terrain of Kashmir is mountainous and at high altitudes; even the best roads, such as National Highway 1