Al Jazeera News : Iraq's Salahuddin province declared three days of mourning on Sunday after a deadly attack blamed on the ISIL (ISIS) armed group, as some criticised the authorities for failing to fight back. Late Saturday, a roadside bomb hit a civilian car on an open road about 200km (120 miles) north of the capital Baghdad, police and a local official said. When security forces arrived at the scene, ISIL fighters opened fire on them. The attack killed at least six Iraqi security officers and four civilians, including one who died of his wounds overnight, according to medics. There was no claim of responsibility by ISIL but both the mayor and police blamed the armed group, which Iraq's government said it defeated in late 2017. That victory came after three years of brutal fighting to wrench back the one-third of Iraqi territory that was captured by ISIL in 2014. Although the fighters no longer hold territory, sleeper cells wage hit-and-run attacks on state infrastructure, particularly in desert areas north of Baghdad. ISIL also launches attacks on the Iran-backed Hashd al-Shaabi militias, also known as the Popular Mobilisation Forces. The Hashd al-Shaabi, founded as a loose network of Shia-majority factions, played a crucial role in defeating ISIL alongside the US-led coalition. Two weeks ago, 11 people were killed in an ISIL attack on a lookout post in al-Radwaniyah on Baghdad's outskirts, areas that are predominantly Sunni Muslim. The attacks have coincided with a new campaign by Iraq's security forces to arrest fighters in hiding across the country - but some say it has not been enough.