BAGHDAD — The United States Embassy in Baghdad was struck by mortar fire late Sunday, with at least one shell hitting a dining facility, slightly injuring one person and causing minor building damage, American officials said.
It was unclear how many of the other four shells launched in the attack landed inside the embassy compound, but the assault alarmed Washington and prompted debate over how to calibrate the response. For security reasons, neither Iraqi nor American military officials, nor the embassy staff in Baghdad, would discuss locations or other specifics of the attack.
The Iraqi government moved quickly to condemn the assault and promised a vigorous investigation.
“We denounce the continuation of these outlawed actions that have the goal of weakening the Iraqi state and violating its sovereignty and the sanctity of diplomatic missions on its soil,” Prime Minister Adel Abdul Mahdi of Iraq said in a statement.
He said Iraqi forces had been ordered to “search and investigate to prevent such attacks” and to arrest those who launched them.
However, in a call with the Iraqi prime minister on Monday, Secretary of State Mike Pompeo said he was “outraged” that groups that he described as armed by Iran were continuing to attack American bases and diplomatic posts in Iraq, according to the State Department’s spokeswoman.
The spokeswoman, Morgan Ortagus, said Mr. Abdul Mahdi committed to better protect United States facilities in Iraq, but Mr. Pompeo said the attacks displayed a failure to curb the armed groups.
“We view last night’s attack on the embassy as an attempt to distract Iraqi and international attention away from the brutal suppression of peaceful Iraqi protesters by Iran and its proxies,” Ms. Ortagus said in a statement describing the call.
The State Department was referring to recent moves by the Iraqi security forces to crack down on protesters who are demanding an end to corruption and the election of a new government. The security forces burned protesters’ tents and used tear gas and live fire to try to force them to flee in Baghdad, Basra and Nasiriya.
A preliminary investigation found that the 120-millimeter mortar shells were launched on Sunday from the Buaytha area, in the south of Baghdad. During the 2007-8 surge of American troops, the area was a redoubt for Al Qaeda in Iraq, a predecessor to the Islamic State.
A senior Iraqi officer investigating the attack said that using coordinates for the flight path, he and his team had located the launchers. The use of mortars and the area from which they were fired, he said, led him to think that the attack could have been carried out by the Islamic State.
Still, the officer, who spoke on condition of anonymity because he is not allowed to speak to journalists, said the weapons were common enough that he could not rule out a Shiite militia faction close to Iran as being responsible.
During the height of Iraq’s civil strife, between roughly 2005 and 2009, both Al Qaeda in Iraq and anti-American Shiite armed groups lobbed mortars at the Green Zone in an effort to hit the American Embassy.
The prime minister’s statement, released within hours of the mortars landing in the embassy compound, appeared aimed at reassuring the Americans that the Iraqis were taking the attack seriously and would mount a vigorous response. The comments stand in stark contrast to the response both to the attack on a military base in Kirkuk, Iraq, at the end of December, which resulted in the death of an American contractor, and to the siege of the United States Embassy on Jan. 1.
In those cases the government said relatively little, especially after the Kirkuk attack.
By contrast, Mr. Abdul Mahdi used his statement on the mortar attack as a way to remind the public, which is divided about whether to have United States troops stay in the country, that using force now against the Americans would risk “dangerous consequences” that could damage Iraqi interests and “drag Iraq into a war.”
The strikes come less than a month after the attack in Kirkuk, which set off a series of retaliatory responses that pushed the United States and Iran to the brink of war. The Americans accused Kataib Hezbollah, an Iraqi militia with close links to Iran, of responsibility in the Kirkuk attack.
There has been no claim of responsibility for Sunday’s rocket attack. Notably, all of the armed groups known to have close ties to Iran went out of their way to deny responsibility and to condemn the attack as damaging to the Iraqi government at a time when it is trying to negotiate the withdrawal of American troops.
The military commander for Asaib al-Haq, one of the groups with links to Iran, denied responsibility both on Asaib’s behalf and that of other similar armed factions, which call themselves the “Resistance Group.”
“We stress that the recent rocket bombing against the evil embassy in Baghdad is not the action of the Iraqi resistance factions, because we have stressed earlier that the resistance factions will not target the embassies and the diplomatic missions in Iraq,” said Jawad Al-Tilaybawi, the commander of Asaib al-Haq.
Similar comments were made by Kataib Hezbollah and the Badr Organization.
While rocket fire in the Green Zone in Baghdad has been a regular occurrence in recent months, the rockets fired on Sunday and last week were more accurate, landing closer to the embassy, according to witnesses.
Often in the past, the rockets have fallen in the Tigris River, or in the Green Zone but far from the embassy compound.
Falih Hassan contributed reporting.