(CNN) -- Gunmen pretending to be an official security force opened fire on police at numerous checkpoints in Haditha, Iraq, early Monday, killing 27, authorities said.
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During the clashes, the attackers raised the black flags of Islamic State of Iraq -- an umbrella group which includes al Qaeda in Iraq. The attackers also left some leaflets behind warning Iraqi security that they will carry out more attacks, Salman said.
MORE: http://www.cnn.com/2012/03/05/world/meast/iraq-violence/index.html?hpt=imi_c2
