The sniper wars of Mosul

A sniper of the Iraqi rapid response forces takes his position during a battle with Islamic State militants in Mosul. REUTERS/Thaier Al-Sudani

An Iraqi civilian takes cover from snipers during a battle against Islamic State militants, at the entrance to Dawasa in Mosul. REUTERS/Alaa Al-Marjani

Iraqi special forces and federal police members hide from a sniper during a battle with Islamic State militants in western Mosul. REUTERS/Zohra Bensemra

Federal police members stand inside a room where they said Islamic State sniper was hiding at a liberated part of Albu Saif village south of Mosul. REUTERS REUTERS/Zohra Bensemra

A sniper of the Iraqi rapid response forces poses for the photographer during a battle with Islamic State militants in Mosul. REUTERS/Thaier Al-Sudani

An Iraqi rapid response member moves from house to house through a hole in a wall to avoid being hit by Islamic State snipers in western Mosul. REUTERS/Zohra Bensemra

Snipers of the Iraqi rapid response forces talk during a battle with Islamic State militants in Mosul. REUTERS/Thaier Al-Sudani

An Iraqi rapid response sniper aims his weapon toward a suspected Islamic State sniper's position in western Mosul. REUTERS/Zohra Bensemra

Iraqi rapid response forces take cover from snipers during battle with Islamic State militants in the Mithaq district of eastern Mosul. REUTERS/Thaier Al-Sudani

A sniper from the Iraqi rapid response forces takes up position at a hospital damaged by clashes during a battle between Iraqi forces and Islamic State militants in the Wahda district of eastern Mosul. REUTERS/Alaa Al-Marjani

Displaced Iraqi civilians, who fled the Islamic State stronghold of Mosul, take cover from snipers in the Mithaq district of eastern Mosul. REUTERS/Thaier Al-Sudani

A man displaced from Tahrir neighborhood cries over his son, who he said was killed by a sniper from the Islamic State, in Mosul. REUTERS/Thaier Al-Sudani

A sniper of the Iraqi rapid response forces take his postion at a damage hospital from clashes during a battle between Iraqi forces and Islamic State militants in Wahda district of eastern Mosul. REUTERS/Alaa Al-Marjani

An Iraqi soldier uses his helmet to distract the opposing sniper during clashes with Islamic State militants at the south of Mosul. REUTERS/Alaa Al-Marjani

A sniper from the Iraqi rapid response forces takes up postion at a hospital damaged by clashes during a battle between Iraqi forces and Islamic State militants in the Wahda district of eastern Mosul. REUTERS/Alaa Al-Marjani

Iraqi rapid response members run to avoid being hit by Islamic State snipers in western Mosul. REUTERS/Zohra Bensemra

A sniper of the Iraqi rapid response forces takes his position during a battle with Islamic State militants in Mosul. REUTERS/Thaier Al-Sudani

Iraqi rapid response forces take cover from snipers during battle with Islamic State militants in the Mithaq district of eastern Mosul. REUTERS/Thaier Al-Sudani

A sniper from Iraq's Federal Police force takes aim at Islamic State positions from the roof of a house on the frontline in Albu Saif, south of Mosul. REUTERS/Alaa Al-Marjani

A sniper from the Iraqi rapid response forces takes up position at a hospital damaged by clashes during a battle between Iraqi forces and Islamic State militants in the Wahda district of eastern Mosul. REUTERS/Alaa Al-Marjani

A sniper team from Iraq's Federal Police prepare their position in Albu Saif, which was recently retaken by Iraqi military forces, south of Mosul. REUTERS/Zohra Bensemra