"Conditions there are among the worst we've seen, and we expect thousands more people to be on their way soon, " said Tarik Kadir, head of the group's Mosul response.
At some point, he predicted, the Iraqi forces will prevail.
The Kurds said the operation aimed to tighten the noose around up the militants holding out in Mosul, where up to 1.5million civilians are thought to remain.
President of the Turkmeneli Associations' Federation, Aydin Beyatli, said he had been to Iraq before its army, Kurdish Peshmerga forces and worldwide coalition led by the USA launched an operation to liberate the northern city of Mosul from Daesh.
Speaking just hours before Votel, Gen. Gary Volesky, commander of the U.S-led coalition's land component, told reporters that Daesh leaders and fighters are leaving Mosul. The Iraqi army and Kurdish Peshmerga forces launched a massive offensive late Sunday to retake Mosul, which ISIS captured in June 2014 before the group took control of much of northern and western Iraq.
He stressed that the battle is led by Iraq and not a foreign invasion, though it has military support from a broad US -led coalition. Visuals and reports filtering out from the battle zone already point to the large-scale use of suicide bombers in armoured trucks and cars taking on the coalition's tanks and advance forces.
Meanwhile, the Iraqi army continued their clashes with IS militants at the edge of the town of Hamdaniyah, some 40 km southeast of Mosul, after repeated attempts to enter the town following the militants showed stiff resistance, the source said.
Iraqi government forces are moving towards Mosul from the south, while their Kurdish allies have been fighting on the eastern and northern frontlines. "Our assessment is that they'll be the people who want to stay and fight. because they really don't have any other place to go", he said.
He did not give a casualty figure, but another officer said five Iraqi soldiers were wounded.
"They're using human shields in there", Gen Townsend said in an exclusive interview with the BBC on Thursday, speaking from an artillery position where U.S. troops were providing fire support to Iraqi forces.
The main Kurdish armed group there, the YPG, is the most powerful element in the Syrian Democratic Forces, a coalition of militias backed by the United States and fighting against Islamic State inside Syria. "They just left some snipers and suicide vehicle bombs", he said.
The Apaches can "see a long range at night" and strike targets from a great distance, which is helping Iraqi forces advance on the city, Maj.
On Monday, Abadi announced the start of the military operation to retake Mosul from Daesh, which is outlawed in many countries, including Russian Federation and the United States.
A senior military commander said Thursday Iraqi special forces have driven Islamic State militants out of a town east of Mosul.
Military operations also appeared to be under way in the town of Bashiqa, north east of Mosul, with thick smoke billowing from the town. About 5,000 US special forces are now embedded with the Peshmerga outside of Mosul.