Washington has blamed paramilitary groups for increasingly regular targeting of rockets and shelling of the base hosting US forces across Iraq and of the area around the US Embassy in Baghdad, Reuters reported.

An attack last month hit the US Embassy compound itself, and a rocket attack on a military base in the north in December killed a US civilian contractor.

There have been no claims for the attacks.

In a report early this month, The New York Times quoted Iraqi military and intelligence officials as raising doubts about who fired the rockets that started the spiral of events that brought the US and Iran to the brink of war.

The United States assassinated top Iranian commander Lieutenant General Qassem Soleimani and Iraqi paramilitary commander Abu Mahdi al-Muhandis in a drone strike in Baghdad last month, after which the region braced for a full-scale conflict. Iran launched its first direct missile attack on a base hosting US forces in response.

According to The New York Times report, the Iraqi officials said they believe it is unlikely that the militia the US blamed for the attack, Khataib Hezbollah, carried it out in December 2019.

Iraqi officials acknowledge that they have no direct evidence tying the Dec. 27 rocket attack to one group or another.

American officials insist that they have solid evidence that Khataib Hezbollah carried out the attack, though they have not made it public.

Khataib Hezbollah has also denied responsibility for the attack, and no group has claimed it.

Iraqi officials said their doubts were based on circumstantial evidence and long experience in the area where the attack took place.

The rockets were launched from Kirkuk Province notorious for attacks by the Daesh, a terrorist group.

Khataib Hezbollah has not had a presence in Kirkuk Province since 2014.

Sunday’s attack, before dawn, was carried out with “small rockets” and caused no casualties, the coalition spokesman said in a statement on Twitter. He provided no further details, Reuters reported.

An Iraqi military statement said three Katyusha rockets had hit the fortified Green Zone which hosts the US Embassy, other foreign missions, and Iraqi government buildings. It said a fourth hit a nearby logistics base for Iraqi paramilitary groups.