Since the beginning of their battle in Mousl, the major challenge which face the Iraqi forces has been the bombs planted by Jihadists loyal to ISIS in different streets and buildings. The tactic adopted by the extremist group aimed to prevent the forces from advancing to the city or at least to slow their movement, while the matter has changed now.

According to a number of Iraqi officers, the extremist group has no qualms about killing civilians, but the presence of a large number of residents in Iraq's second city discouraged the jihadists from extensively sowing it with explosives.

Staff Lieutenant General Abdulghani al-Assadi, a top commander in the elite Counter-Terrorism Service, said that the Previous urban battlefields in Iraq's war against IS were largely depopulated, while the country's forces moved in.

He added, in a statement to "Globe and Mail" Newspaper, that Mosul still sheltered a million-plus people when the offensive to retake it was launched three months ago, saying that If explosives had been widely planted by the jihadists ahead of the battle, they would have been at risk of being triggered before Iraqi forces arrived.

So while the systematic mining of roads and rigging of buildings with bombs has arguably been ISIS signature, defense system against Iraqi forces, in Mosul, the jihadists had to change tack.