Iraqi forces said Tuesday (June 20th) they were fighting fierce battles with the "Islamic State of Iraq and Syria" (ISIS) and rescuing escaping civilians as they pursued their offensive against Mosul's Old City, AFP reported.

Staff Lt. Gen. Abdulghani al-Assadi, a senior commander in the Counter-Terrorism Service (CTS), said the battle was proceeding as expected but that progress was slow.

"Things are good and the battle is going as planned," he told AFP.

"We have many obstacles -- the nature of the land, the nature of the construction, the roads and the civilian population -- all of which make us slow down our work."

He said civilians were escaping the Old City, with up to 400 approaching the positions of Iraqi forces on Monday.

Despite the slow advance, Iraqi forces on Tuesday liberated new areas in west Mosul, the Ninawa Operations Command said.

"The 9th Armoured Division has liberated the southern part of al-Shefaa neighbourhood, and retaken Bash Tapia Castle, the juvenile prison and Yahya Abu al-Qassim shrine," Lt. Gen. Abdul Ameer Rashid Yarallah said in a statement.

"Our units have also retaken the Ninawa Health Department building, Maria Church and the fifth bridge," he said.