BAGHDAD — A rocket was fired into the Iraqi capital’s heavily fortified Green Zone Sunday night, landing less than a mile from the U.S. Embassy, an Iraqi spokesman said.

The apparent attack, which Iraq’s state-run news agency said did not cause any casualties, came amid heightened tensions across the Persian Gulf. The White House ordered warships and bombers to the region earlier this month to counter an alleged threat from Iran.

The U.S. also has ordered nonessential staff out of its diplomatic posts in Iraq.

No one claimed responsibility for the attack that took place after sunset when many Baghdad residents were indoors breaking their fast during the Muslim holy month of Ramadan.