Three people were killed and 15 people were injured Thursday when a rocket was fired into the International Zone in Baghdad, the U.S. Embassy said.
Two Ugandans and one Peruvian were killed, while two of the injured were American citizens.
All of the dead and injured were working for a U.S. government security contractor that protects U.S. government facilities in Iraq, the embassy said in a statement.
The International Zone is the area formerly known as the Green Zone.
The U.S. Embassy in Baghdad came under artillery fire earlier this month as Vice President Joe Biden and his wife were visiting the country.