A rocket landed in Baghdad's Green Zone near the huge U.S. Embassy compound amid heightened tensions in the region as Washington withdraws personnel from Iraq and President Donald Trump issued a warning to Iran.
Iraq's state-run news agency said there were no casualties as a result of the Katyusha rocket exploding less than 1 kilometer from the U.S. Embassy on May 19.
It was the first such rocket attack in the Green Zone -- a high-security area where many foreign and Iraqi officials, including parliament and the prime minister, are based -- since September 2018.
An Iraqi military spokesman, Brigadier General Yahya Rasul, told AP that the rocket fell near Iraq's statue of the Unknown Soldier, and was being investigated.
Rasul said the rocket was believed to have been fired from the eastern part of Baghdad, which is where some Iranian-backed militias are based.
But AFP reported that a police source said the rocket was "fired from an open field" in southern Baghdad.
The United States accused Iran last year of targeting U.S. installations.
After Washington shut down its consulate in the southern Iraqi city of Basra last year, U.S. Secretary of State Mike Pompeo blamed Iranian militants for "indirect fire" on the building.
The Katyusha rocket attack came the same day that U.S. oil giant Exxon Mobil evacuated around 60 foreign staff from an oil field in Iraq.
Iraqi Oil Minister Thamir Ghadhban said in a May 19 statement that ExxonMobil's decision was "unacceptable and unjustified" and had "nothing to do with the security situation or threats in the oilfields in of southern Iraq," adding that it was "political."
Washington has ordered a beefing up of U.S. military assets in the Middle East and Persian Gulf, citing possible threats from Iran, and the State Department also ordered the evacuation of all nonessential personnel from the U.S. Embassy in neighboring Iraq.
The Federal Aviation Administration (FAA) on May 16 warned U.S. commercial airliners flying over the waters of the Persian Gulf that they risked being misidentified.
The ExxonMobil evacuation started early on May 18 in Iraq's southern province of Basra, with employees flown to the United Arab Emirates.
Ihsan Abdul Jabbar, the head of Iraq's state-owned South Oil Company, said operations at the field, run by ExxonMobil, were continuing as normal with the help of Iraqi technicians.
In Washington, U.S. President Donald Trump issued a threatening tweet to Iranian officials: "If Iran wants to fight, that will the official end of Iran. Never threaten the United States again."
Iran has dismissed the allegations from Washington that there were "imminent threats" from Tehran and accused the United States of an "unacceptable" escalation of tensions.
In May 2018, Trump pulled the United States out of the 2015 landmark nuclear deal which curtailed Iran's nuclear ambitions in exchange for relief from crippling sanctions. Since then Washington has steadily stepped up its rhetoric and reimposed sanctions.
Earlier this month, Trump dispatched an aircraft carrier and B-52 bombers to the Persian Gulf, as well as an amphibious assault ship and a Patriot missile battery.
Both sides have said they do not want a war.
Saudi Foreign Minister Adel al-Jubeir said on May 19 that Riyadh also did not want military conflict with Iran but that "if the other side chooses war, the [Saudi] kingdom will fight this with all the force and determination and it will defend itself, its citizens, and its interests."
Saudi Arabia claims that two of its oil tankers were targeted last week in an act of sabotage of the coast of the United Arab Emirates. Iran-supported Huthi rebels also claimed responsibility for a drone attack on a Saudi oil pipeline.