A rocket attack targeted the Iraqi capital Baghdad’s heavily fortified Green Zone early Tuesday.    

A Katyusha rocket struck an empty house, according to a statement by Iraq’s state-run Security Media Network.  

No casualties were reported and there was no immediate claim of responsibility. 

Sirens were heard at the US embassy compound when the attack took place.  

The Green Zone is a highly fortified zone in the capital where government headquarters and foreign missions are located.