During the first stages of the Battle of Mosul, the coalition of Iraqi forces was simply preoccupied with dishing out salvos in recovering some areas from the Islamic State of Iraq and Syria (ISIS). Now they have to keep these neighborhoods secure by ridding away the dreaded car bombs.
If the best defense is a good offense, then one might be inclined to believe that ISIS is still doing a fine job fighting back despite losing their hold in the eastern blocks of Mosul City. The ability of the enemy to insidiously integrate themselves among the million or so civilians enables them to carry out covert attacks such as suicide car bombs.
The Iraqi forces conduct highly-sensitive search-and-destroy operations to completely turn the eastern neighborhoods into a green zone. According to an article published by the Military Times, the hunt for car bombs and incognito fugitives is definitely the most unnerving part of the Iraqi forces' responsibility in the Battle of Mosul.
The involvement of civilians is always an unavoidable complication. A comprehensive coverage presented by the New York Times describes a more complex analysis of the current tasks undertaken by Sunni-majority Iraqi forces. The involvement of the Shia militia is a double-edge sword that cuts both ways.
An article published by Jobs & Hire feature the mobilization of Shiite rebels in Tal Afar that essentially cuts off the main logistical lifeline between Iraq and Syria. On one hand, they keep the ISIS preoccupied, enfeebling their frontlines and sealing their exit routes. However, the possibility of reigniting the Sunni-Shia feud with Shiite militia attacking civilians is also highly likely given their long history of unresolved injustices.
The Iraqi forces are treading more lightly, avoiding a heavy-handed approach while this part of the operation is being conducted in the midst of innocent civilians. Searching for car bombs and its incognito operators is simply a worse-case scenario that leaves the Iraqi forces vulnerable.