raqi security forces advance in Qayara, south of Mosul, to attack Islamic State militants in Mosul, Iraq, October 18, 2016. (REUTERS)

A member of Peshmerga forces rides a motorcycle in the east of Mosul during an operation to attack Islamic State militants in Mosul, Iraq, October 18, 2016.(RUTERS)

Peshmerga forces sit in the back of a vehicle in the east of Mosul during an operation to attack Islamic State militants in Mosul, Iraq, October 18, 2016.(Reuters)

Iraqi security forces advance in Qayara, south of Mosul, to attack Islamic State militants in Mosul, Iraq, October 18, 2016. (Reuters)

A member of Iraqi security forces stands with his weapon in Qayara, south of Mosul, during an operation to attack Islamic State militants in Mosul, Iraq, October 18, 2016. (Reuters)

Iraqi security forces gather in Qayara, south of Mosul, to attack Islamic State militants in Mosul, Iraq, October 18, 2016. (Reuters)

Peshmerga forces advance in the east of Mosul to attack Islamic State militants in Mosul, Iraq, October 18, 2016. (Reuters)

Iraqi security forces advance in Qayara, south of Mosul, to attack Islamic State militants in Mosul, Iraq, October 18, 2016. (Reuters)

Iraqi security forces advance in Qayara, south of Mosul, to attack Islamic State militants in Mosul, Iraq, October 18, 2016. (Reuters)