Mosul- Iraqi forces entered on Sunday the heart of Mosul and tightened the noose on ISIS militants after cutting off the group's last link to the western part of the city.
The militants are vastly outnumbered and outgunned by Iraqi forces backed by a US -led coalition and are defending their last major stronghold in Iraq using suicide vehicle bombs, snipers and mortars.
Eastern Mosul was liberated by government forces in January.
"We're moving on the old bridge. and then we will free that area and hopefully in a few days we'll liberate the west side of Mosul", said one Iraqi captain.
"The battle is not easy... we are fighting an irregular enemy who hides among the citizens and uses tactics of booby-trapping, explosions and suicide bombers", Brigadier General Yahya Rasool said.
One resident of Wadi Hajar district said that that a store giving out food aid exploded killing and injuring many civilians, including "young children".
The jihadists have held Mosul, Iraq's second city, since 2014.More news: North double ends Ireland's Six Nations hopes
Human Rights Watch said in a report that as many as 600 people were killed in the Badush prison massacre, which took place on the same day that Islamic State militants captured Mosul in June 2014.
Federal police and Rapid Response units said they had entered the Bab al-Tob area of the Old City, where the fight is expected to be toughest due to narrow alleyways through which armored vehicles can not pass.
Almost 100,000 people have been displaced since the operation to liberate western Mosul began last month, according to Iraq's Ministry of Migration and Displaced. It is very evident that a permissive environment is emerging for another Sunni insurgency in the vacuum of control left by ISIS, into which other actors would surely emerge.
Fierce fighting is under way against fighters with the Islamic State terrorist militia there, the source added on condition of anonymity.
The remains of hundreds of mainly Shia inmates killed by Daesh militants when they overran a prison in northern Iraq more than two years ago have been unearthed by Shia jihadists retaking the area from the group, a spokesman said.
In a 2014 report, Human Rights Watch said ISIS killed hundreds of prisoners, majority Shi'ites, when it seized Mosul that year.