A number of rockets were fired on Thursday and Friday at bases housing troops of the US-led anti-jihadist coalition in Iraq and Syria, security officials and war monitors said.
Such attacks were frequent early in the war between Israel and Hamas Palestinian militants in Gaza but have since largely stopped.
An Iraqi security source said four rockets fell near the Ain al-Asad base in Anbar province.
Another security official said the attack was caused by “a drone and three rockets” which fell close to the base perimeter.
A US official said initial reports suggested the missiles fell outside the base, but caused no injuries or damage to the base.
All the sources spoke on condition of anonymity as they were not authorised to speak to the media.
At least one rocket fell near a coalition base at the Conoco gas field in eastern Syria’s Deir Ezzor province, according to the Britain-based Syrian Observatory for Human Rights war monitor.
The observatory said an explosion was heard in the area, but there were no immediate reports of casualties.
The monitor, which relied on Syrian insiders, said the rockets were fired from “areas controlled by pro-Iran militia groups.”
There was no immediate claim of responsibility for any of the attacks.
Similar attacks on US-backed troops by Iran-backed armed groups in Iraq have largely stopped in recent months.
The latest attack comes after a security meeting this week between Iraqi and US officials in Washington on the future of the international anti-jihadist coalition in Iraq. Iran-backed groups have demanded the return of the coalition.
The US Defense Department said on Wednesday that “the delegations reached agreement on the concept of a new phase of bilateral security relations.”
This would include “cooperation through liaison officers, training, and traditional security cooperation programs”.
On 16 July two drones were fired at the Ain al-Asad base, one of which exploded inside, but caused no injuries or damage. A senior security official in Baghdad said at the time that he believed the attack was designed to “embarrass” the Iraqi government ahead of a security meeting.
Over three months, as regional tensions escalated over the Israel-Hamas war in Gaza, United States troops across the Middle East, primarily in Iraq and Syria, have been targeted with rockets and drones more than 175 times.
The Islamic Resistance of Iraq, a loose coalition of Iran-backed groups, claimed responsibility for most of the attacks and said they were in solidarity with Gaza Palestinians.
In January, a drone attack blamed on these groups killed three US soldiers at a base in Jordan. In retaliation, the US military carried out dozens of strikes against Tehran-backed militias.
Since then, attacks on American troops have largely stopped.
Baghdad has sought to ease tensions by holding talks with Washington on the future of the US-led coalition’s mission in Iraq.
The US military has about 2,500 troops deployed in Iraq and 900 in Syria with the international coalition.
The coalition was deployed to Iraq in 2014 at the government’s request to help fight the Islamic State group, which had seized large parts of Iraq and neighbouring Syria.
Remnant IS militants still carry out attacks and ambushes in both countries.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
