With operations to sweep the remnant Islamic State forces out of Fallujah wrapped up, the focus of Iraqi security forces has shifted to a slow-moving approach toward Mosul , the heart of Islamic State operations in Iraq. Iraqi advances over the past few weeks, intensifying over the past few days, on both sides of the Tigris River have squeezed Mosul's ability to supply Islamic State operations to the south and have put significant pressure on Islamic State militants still in Hawija district, a relatively fertile slice of land in Tamim province populated largely by Sunni Iraqis and sandwiched between the Tigris and Iraqi Kurdistan. East of the Tigris near Makhmur, Iraq has been building up its forces for weeks in preparation for cutting off Hawija from its critical Mosul supply lines. Iraqi Kurdistan has been the staging area for many of these operations, and there is significant Kurdish peshmerga participation.