Shafaq News/ Sirens sound in the heavily fortified Green Zone, downtown the Iraqi capital, Baghdad.

A security source said on Saturday that officers in charge of the security of the US embassy in Baghdad triggered the Sirens in an experimental drill ahead of the transition of the Coalition forces to non-combat missions. 

The US embassy compound in the Green Zone has been a frequent target of recurring rocket attacks launched by unidentified parties. The US administration accuses Iran-backed paramilitary factions of executing those attacks.