On 13 December 2001, a group of masked, armed men with fake IDs stormed Parliament House in Delhi. The terrorists managed to kill several security guards, but the building was sealed off swiftly and security forces cornered and killed the men who were later proven to be Pakistan nationals. Vajpayee ordered Indian troops to mobilise for war, leading to an estimated 500,000 to 750,000 Indian soldiers positioned along the international border between India and Pakistan. Pakistan responded by mobilising its own troops along the border. A terrorist attack on an army garrison in Kashmir in May 2002 further escalated the situation. As the threat of war between two nuclear capable countries and the consequent possibility of a nuclear exchange loomed large, international diplomatic mediation focused on defusing the situation. In October 2002, both India and Pakistan announced that they would withdraw their troops from the border.