The long-anticipated campaign to reclaim Mosul from the Islamic State began Monday. It is the largest military operation in Iraq since U.S. forces left five years ago.
The Battle for Mosul
![Peshmerga forces advance in the east of Mosul to attack Islamic State militants in Mosul, Iraq, Oct. 17, 2016.](https://gdb.voanews.com/77D6D402-7526-4B91-A191-6690407A5E09_w1024_q10_s.jpg)
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Peshmerga forces advance in the east of Mosul to attack Islamic State militants in Mosul, Iraq, Oct. 17, 2016.
![Smoke rises from Islamic state positions after an airstrike by coalition forces in Mosul, Iraq, Oct. 17, 2016.](https://gdb.voanews.com/411ABDBE-DF01-45D0-B4DE-D78693DBC17E_w1024_q10_s.jpg)
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Smoke rises from Islamic state positions after an airstrike by coalition forces in Mosul, Iraq, Oct. 17, 2016.
![This photo released on his official Facebook page shows Iraqi Prime Minister Haider al-Abadi, center, surrounded by top military and police officers as he announces the start of the operation to liberate the northern city of Mosul from Islamic State milit](https://gdb.voanews.com/A0B57A73-C5A1-4045-9E4B-0C8D1E5AC5C4_w1024_q10_s.jpg)
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This photo released on his official Facebook page shows Iraqi Prime Minister Haider al-Abadi, center, surrounded by top military and police officers as he announces the start of the operation to liberate the northern city of Mosul from Islamic State milit
![Kurdish Peshmerga fighters stand on top of a military vehicle as they advance towards villages surrounding Mosul, in Khazer, about 30 kilometers (19 miles) east of Mosul, Iraq, Oct. 17, 2016.](https://gdb.voanews.com/11FE558B-2351-4F43-9CE5-8178B975CA58_w1024_q10_s.jpg)
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Kurdish Peshmerga fighters stand on top of a military vehicle as they advance towards villages surrounding Mosul, in Khazer, about 30 kilometers (19 miles) east of Mosul, Iraq, Oct. 17, 2016.