Iraqi forces try to drive Islamic State from their last major stronghold in the country. Street battles continued with both sides firing mortar rounds and automatic weapons at each other’s positions, while Iraqi troops also responded with artillery. Clashes were most intense in the al-Bakr neighbourhood. Sniper duels played out from rooftops in the mostly residential areas, where the majority of buildings are two stories high. Lieutenant-Colonel Saad Alwan, from Iraq’s counter-terrorism unit, told Al Jazeera the street battles were ferocious. “We’re facing fierce resistance, they’re digging trenches and using car bombs,” Alwan said. More evidence of daunting fortifications emerged on Saturday, with satellite images showing ISIL had set up defences to bog down advancing forces, including rows of concrete barricades, earth berms, and rubble blocking key routes leading to the centre of the city.