The two armoured divisions secured the territory bounded by the cities of Khorramshahr, Ahvaz, Susangerd, and Musian. On the central front, the Iraqis occupied Mehran, advanced towards the foothills of the Zagros Mountains, and were able to block the traditional Tehran–Baghdad invasion route by securing territory forward of Qasr-e Shirin, Iran. On the northern front, the Iraqis attempted to establish a strong defensive position opposite Suleimaniya to protect the Iraqi Kirkuk oil complex. Iraqi hopes of an uprising by the ethnic Arabs of Khuzestan failed to materialise, as most of the ethnic Arabs remained loyal to Iran. The Iraqi troops advancing into Iran in 1980 were described by Patrick Brogan as "badly led and lacking in offensive spirit". The first known chemical weapons attack by Iraq on Iran probably took place during the fighting around Susangerd.