In addition to scattered but virtually continuous clashes, nine major confrontations between the NLA and Khomeini's forces took place from Tuesday morning until Thursday evening. The Guards forces, arriving by air and land, attacked the town from various directions. All the attacks and counterattacks were characterized by their intensity and length. In many cases, the NLA forces fought the enemy in hand-to-hand combat. The confrontations lasted from 10 to 30 hours.
It should be noted that until Thursday evening, when the NLA decided to withdraw from Islamabad, it had prevailed over the enemy in all of these battles. Despite constant reinforcements which added fresh troops and increased their numbers, at no time was the NLA driven back from any of its gains.
The first major confrontation raged from 6 am on Tuesday until the early hours of Wednesday morning, south of Islamabad on the hills overlooking Sugar Factory road toward 11am. Three NLA brigades put up a strong defense against Guards attacking from several directions. The Guards Corps' 5th Nasr, 43rd Imam Ali, and 17th Ali-ibn-Abitaleb divisions wanted to capture the heights overlooking the town and then break through. Their high command, the Khatam operational HQ, insisted that they begin their attack before their support artillery arrived. In the first stage, they could not advance despite a four-hour clash.