A group of 10 terrorists, including members of the Tehrik-e-Taliban Pakistan and factions of the JeM and Lashkar-e-Jhangvi, carried out the attack that began on Saturday, said Major General Athar Abbas, chief of the Inter-Services Public Relations.
"Their target was to take hostage senior officers of the General Headquarters (in Rawalpindi) and then place their demands. Their main demand was (the release of) a long list of over 100 terrorists, including high-profile leaders from different groups, who are in the custody of the government," Abbas told mediapersons.
While five terrorists were gunned down near a check post outside the headquarters on Saturday afternoon, four more were killed when commandos of the Special Services Group carried out an operation on Sunday to free 39 hostages held by the attackers.
Eleven army personnel, 8 terrorists and three hostages were killed on Saturday and Sunday in the storming of the army headquarters and the subsequent rescue operations.
Commandos captured Aqeel alias Dr Usman, a former soldier who was the alleged mastermind behind the attack, after he was severely injured in an explosion.
The terrorists made other demands, such as a call for ending the United States' presence in Pakistan, Abbas said. The attackers were clad in army uniforms and were 'well trained.'
They were carrying automatic weapons, mines, grenades, improvised explosive devices and suicide jackets, he said. The military had on Saturday morning intercepted a conversation between South Waziristan-based Taliban commander Waliur Rehman and another militant leader in which they discussed the attack.
"During the conversation, Rehman asked his subordinate to pray for the success of the fidayeen attack on the General Headquarters," Abbas said.
Aqeel hails from Kahuta near Rawalpindi while the remaining terrorists were from South Waziristan and Punjab province. The terrorists were trained in South Waziristan for the attack, Abbas said.
Leaders who had split from the JeM and LeJ had tied up with the Pakistani Taliban in the tribal areas to carry out attacks, he said. Asked if the attack would speed up the army's plans to launch operations against militants in South Waziristan, Abbas said the government had already decide to launch an offensive against the Tehrik-e-Taliban Pakistan, which is responsible for '80 per cent of attacks' across the county.
The military is studying the situation and will 'decide what is the best time for the operations,' he said. In response to another question on whether India was in any way linked to the attack, Abbas said an inquiry to be conducted by the army will 'ascertain if any outside agencies were involved' in the incident.