A rocket attack on Baghdad's heavily fortified Green Zone has killed three foreign security workers and injured 15 more, according to the US Embassy.The dead and wounded are all employees of the US contractor Triple Canopy.
Two Ugandans and a Peruvian died, and two Americans were among the those wounded when the rocket struck on Thursday.
Triple Canopy, based in Herndon, Virginia, guards security checkpoints for US military facilities in Iraq.
The firm was founded by US special forces veterans.
"This cruel and senseless attack will not deter the United States from carrying out its goal of working with the Iraqi government and people to build a democratic future," the embassy said.
Iraqi police said it was a mortar, not a rocket, that struck the Green Zone.
In September last year, several mortars or rockets landed in the Green Zone near to the US Embassy, during a visit by United States Vice-President Joe Biden.