 The KDP estimated that 58,000 of its supporters had been expelled from PUK-controlled regions from October 1996 to October 1997.The PUK says 49,000 of its supporters were expelled from KDP-controlled regions from August 1996 to December 1997.The PUK and KDP later co-operated with American forces during the 2003 invasion of Iraq, routing Iraqi forces with the help of American air power and overrunning much of northern Iraq including the cities of Kirkuk and Mosul.