The late Monday attack on camp Taji, about 27 kilometers (17 miles) north of Baghdad, is the second on a military post housing U.S. personnel. An attack on an air base, also housing U.S. trainers, north of Baghdad on Saturday caused a small fire.
The brief military statement Monday said Katushya rockets were used. Two military officials speaking on condition of anonymity because investigation is still underway said the rockets landed near an Iraqi air defense unit.
The attack comes amid rising tension in the Middle East between the United States and Iran.