Rockets hit Baghdad's Green Zone, home to the US embassy, on Thursday (June 18th), the fifth such attack in 10 days, security sources inside the high-security district said.
AFP journalists heard at least three explosions, followed by the sound of sirens in the Green Zone.
There were no immediate reports of casualties or damage.
Like previous attacks, there was no claim of responsibility.
Since October, at least 32 attacks have targeted US interests in Iraq that the US has blamed on Iran-backed Iraqi militias.
The resumption of attacks after weeks of calm coincides with the launch on June 11th of a strategic dialogue between Washington and Baghdad that aims to better define their military, economic and cultural relationship.
As part of the talks, Washington has already pledged to continue reducing in-country troop levels, which numbered about 5,200 last year.