Iraq retakes Tikrit

Shi'ite paramilitary fighters launch a rocket towards Islamic State militants in Tikrit March 31, 2015. REUTERS/Alaa Al-Marjani

Iraqi security forces and Shi'ite paramilitary fighters hold an Islamist State flag, which they pulled down in Tikrit, March 31, 2015. REUTERS/Alaa Al-Marjani

Shiite paramilitary fighters gather near a building of Salahuddin Municipality Directorate in Tikrit March 31, 2015. REUTERS/Stringer

Shiite paramilitary fighters inspect a building in Tikrit March 31, 2015. REUTERS/Stringer

A member of the Iraqi security forces carries his weapon as he watches smoke rise from a scene of clashes between the Iraqi army and Islamic State militants in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

A member of the Iraqi SWAT troopers gestures in Tikrit March 31, 2015. REUTERS/Stringer

A member of the Iraqi security forces checks his weapon in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

A Shi'ite paramilitary fighter puts Iraqi flags on a wall painted with the black flag commonly used by Islamic State militants in Tikrit March 31, 2015. REUTERS/Stringer

An Iraqi security forces military vehicle drives through Tikrit March 31, 2015. REUTERS/Stringer

Shi'ite paramilitary fighters gesture in Tikrit March 31, 2015. REUTERS/Stringer

Shi'ite paramilitary fighters ride a vehicle past a wall painted with the black flag commonly used by Islamic State militants, with the palaces of former Iraqi president Saddam Hussein behind them, in Tikrit, March 31, 2015. REUTERS/Stringer

Iraqi security forces gather with their weapons at a building in Tikrit, March 27, 2015. REUTERS/Thaier Al-Sudani

A plume of smoke rises above a building during an air strike in Tikrit, March 27, 2015. REUTERS/Thaier Al-Sudani

A member of the Hashid Shaabi (Popular Mobilization) forces allied with Iraqi forces against the Islamic State, holds Iraq's national flag in Tikrit, March 28, 2015. REUTERS/Thaier Al-Sudani

Iraqi army soldiers eat a meal with members of the Hashid Shaabi (Popular Mobilization) forces, which are allied with Iraqi forces, in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

Smoke rises during clashes between Islamic state militants and Iraqi army in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

Iraqi security forces stand on their military vehicles in Tikrit, March 27, 2015. REUTERS/Thaier Al-Sudani

A member of the Iraqi security forces uses binoculars as he keeps watch in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

An air strike on a hospital is pictured in Tikrit, March 27, 2015. REUTERS/Thaier Al-Sudani

Hashid Shaabi (Popular Mobilization) forces allied with Iraqi forces against the Islamic State, keep watch in Tikrit, March 28, 2015. REUTERS/Thaier Al-Sudani

Iraqi security forces launch a rocket towards Islamic State militants during clashes at a frontline in Tikrit, March 28, 2015. REUTERS/Thaier Al-Sudani

Shiite clerics from Hashid Shaabi (Popular Mobilization) forces, allied with Iraqi forces against the Islamic State, pray in Tikrit, March 28, 2015. REUTERS/Thaier Al-Sudani

Iraqi security forces gather with their weapons at a building in Tikrit, March 27, 2015. REUTERS/Thaier Al-Sudani

Iraqi security forces ride on the back of a truck in Tikrit, March 28, 2015. REUTERS/Thaier Al-Sudani

Members of the Hashid Shaabi (Popular Mobilization) forces, which allied with Iraqi forces, chant slogans against the Islamic State in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

A member of the Iraqi army carry a rocket as he prepares to launch towards Islamic State militants in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

Iraqi security forces ride on a military vehicle with their weapons in Tikrit, March 28, 2015. REUTERS/Thaier Al-Sudani

Smoke rises during clashes between Islamic state militants and the Iraqi army in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani

A Shiite cleric from Hashid Shaabi (Popular Mobilization) forces, allied with Iraqi forces against the Islamic State, walks next to a military vehicle in Tikrit, March 28, 2015. REUTERS/Thaier Al-Sudani

Smoke rises during clashes between Islamic state militants and the Iraqi army in Tikrit, March 30, 2015. REUTERS/Alaa Al-Marjani