The Pakistani-backed forces took over the bunker complex around April and May 1999, but the winter snows had melted earlier than usual and an Indian reconnaissance team sent to inspect the bunkers was wiped out by them. The Indian Army, alerted to the presence of these militants, responded quickly and massed a force of around 30,000 men to re-take the Kargil hills. The Pakistani-backed forces were detected very early in the operation and were not adequately prepared as they still needed another month or so before they properly established themselves on the Kargil hills, as they were short on heavy weaponry, ammunition, food, shelter, and medicine. However Pakistani troops initially managed to retain most of the heights in spite of continuous Indian attacks. Two months into the conflict, Indian troops had slowly retaken most of the ridges that were encroached by the infiltrators; according to official count, an estimated 75–80% of the intruded area and nearly all high ground had returned to Indian control.