An Iraqi policeman stands guard outside the Sunni Al-Hassan Mosque in Basra, 340 miles (550 kilometers) southeast of Baghdad, Iraq, Tuesday, Sept. 17, 2013. Gunmen have shot dead over a dozen Sunnis in Iraq's Shiite-majority city of Basra over the past two weeks, following threats to retaliate against them for attacks on Shiites in other parts of Iraq, police and a Sunni community leader said. (AP Photo/ Nabil al-Jurani)

Photo by: Nabil al-Jurani

An Iraqi policeman stands guard outside the Sunni Al-Hassan Mosque in Basra, 340 miles (550 kilometers) southeast of Baghdad, Iraq, Tuesday, Sept. 17, 2013. Gunmen have shot dead over a dozen Sunnis in Iraq's Shiite-majority city of Basra over the past two weeks, following threats to retaliate against them for attacks on Shiites in other parts of Iraq, police and a Sunni community leader said. (AP Photo/ Nabil al-Jurani)