At least eight people were killed in a strike on an Iranian-backed militia in Syria near the Iraqi border on Thursday night, the Syrian Observatory for Human rights said Friday.

None of those killed were Syrian citizens, the observatory added.

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Lebanon's Al-Mayadeen news outlet attributed the strike to Israel, while the Syrian Observatory for Human Rights said planes targeted positions belonging to pro-Iran militias in the Boukamal area, near the border with Iraq.

The Britain-based organization, which documents the war in Syria through a network of activists on the ground, said that the planes struck among other targets weapons depots and vehicles belonging to the militias. It reported several explosions in the border area.

Deir Ezzor 24, an activist collective that reports on news in the border area, said that the planes strikes hit trucks carrying weapons and depots for ballistic missiles in the area. Omar Abu Laila, a Europe-based activist from Deir el-Zour who runs the group, said that the attack triggered “a huge explosion” heard in the Syrian-Iraqi border.

The Sound and Picture, another activist collective in Syria's eastern Deir el-Zour area, said that “unidentified planes" struck militia targets in Boukamal.

There was no immediate comment from Syria or Iraq, and the reports could not be independently confirmed.

A series of strikes in Iraq have been recently attributed to Israel, some of them near the Syria-Iraq border and the Albukamal-Qaim crossing. The attacks targeted Iran-backed Shi'ite militias and their convoys tasked with smuggling weapons into Syria.

Iraq tensely watches battles unfold on its soil

In August, the New York Times quoted senior U.S. officials as saying that Israel had carried out "several strikes" in Iraq.

For months, Iraqis have watched with deepening anxiety as tensions between Iran-backed militias and U.S. forces soared, fearing their long-beleaguered country would turn into a battleground for direct and open conflict between America and Iran.

Those fears were realized in the past week when a U.S. airstrike killed Iran’s top military commander, Gen. Qassem Soleimani after he landed at Baghdad airport, and Iran responded by firing over a dozen missiles at Iraqi military bases housing American troops.

Tensions eased on Wednesday when U.S. President Donald Trump signaled that Washington was stepping away from escalation.

But it remains to be seen what effect the clashes will have on Iraq’s willingness to allow American troops to remain on Iraqi soil.

In the immediate aftermath of Soleimani’s killing, Iraq’s Parliament angrily voted to expel the estimated 5,200 U.S. forces stationed in the country to fight the Islamic State group — a nonbinding measure that needs the approval of the Iraqi government.

The easing of tensions in the wake of the Iranian missile attack, which caused no casualties, appears to have tempered the political resolve to immediately push American troops out.

Weeks of tit-for-tat violence illustrated how Iraq’s leadership was powerless to prevent the two sides from battling on its soil, first through proxies, then face to face.

The violence was set off when a rocket attack blamed on the Iranian-backed militia group Kataib Hezbollah, or Hezbollah Brigades, caused the death of an American contractor at a base in Kirkuk province. The U.S. replied with a barrage of strikes on the militia’s bases, killing at least 25 people.

Iraqi Prime Minister Adel Abdul-Mahdi got a call from U.S. Defense Secretary Mark Esper a half-hour before the strike to tell him of U.S. intentions. He urged Esper to call off the plan, “but there was insistence,” according to a statement from the premier’s office.

The militia fighters’ deaths prompted enraged supporters to attack the U.S. Embassy in Baghdad for two days, breaking into the compound and setting fires.

The U.S. then killed Soleimani in a drone strike that also cost the lives of a senior Iraqi militia leader and others.

Shortly before Iran stuck back with its missile barrage against two Iraqi military bases in Ain al-Asad and Irbil that house American troops, the Iranians informed Abdul-Mahdi of its plans, according to his office.

The morning after, anti-government Iraqi demonstrators in Baghdad set fires and closed roads near Tahrir Square.