According to Iraqi officials and outside analysts, the Tikrit offensive against Islamic State (IS) militants to retake the strategically located city is vital to roll back IS' gains in Iraq and Syria.
Strong resistance from IS extremists is expected to intensify in the coming days, reported the Washington Times.
Iraqi Defense Minister Khaled al-Obeidi said that the Tikrit offensive is "essential to opening a corridor" for Baghdad-aligned forces to move towards the northern region in Mosul.
At least 30,000 men are involved in the offensive and the forces have come up against suicide bombers, sniper fire, heavy machine guns and mortars as they close in on Tikrit, said Iraqi officials.
Regional analysts said that the Tikrit offensive is significant both militarily and politically.