In the sixth major confrontation, which continued on and off from 6 o'clock on Wednesday morning until Thursday afternoon, the regime's newly arrived forces, unable to enter the town from the south, advanced from southwestern Islamabad toward the hills behind Allaho-Akbar garrison. They hoped to cut the Kerend-Islamabad road by capturing the garrison. An NLA brigade countered Khomeini's forces. The regime's forces, including a massive force attached to the Boroujerdi garrison, had no heavy weaponry and could not withstand the heavy fire of an NLA tank battalion. The NLA recaptured the four hills located behind Allaho-Akbar garrison. Long-range clashes continued until 6 am, Thursday. All the western and northwestern areas of Islamabad, including the silo at the northwestern end of the town, were under NLA control.
At 6 am, Thursday, enemy forces attacked again from three directions to capture the hills behind the garrison. This attack was defeated, but the enemy reorganized its forces and captured a hill located at the southernmost point. A bloody battle ensued and the hill changed hands twice. The NLA forces ultimately captured the hill after a fierce battle and held it until they evacuated the town. On Thursday evening.Khomeini's forces were not able to make any more advances. In this series of clashes, the enemy suffered more than 700 casualties.