TOPSHOTS Iraqi security forces and volunteer Shiite fighters, known as the Popular Mobilisation units, gather in the city of Samarra on March 5, 2015, ahead of moving into Tikrit. Some 30,000 Iraqi security forces members and allied fighters launched an operation to retake Tikrit, the largest of its kind since Islamic State (IS) group forces overran swathes of territory last June. AFP PHOTO / AHMAD AL-RUBAYE