The United States carried out an airstrike just outside Aleppo, killing at least 42 people and injuring dozens more at a mosque during evening prayers Thursday, reports said.

Journalist Samuel Oakford reported CentCom confirmed it had conducted an airstrike in Idlib in the past six hours.

A photo of a missile fragment taken by a Dutch journalist indicated an American missile was used in the strike although other reports fingered Russia.

The Syrian Observatory for Human Rights said the mosque was full of worshippers for evening prayers when it was hit in the village of al-Jinah in a rebel-held area of northwest Syria that includes Idlib province and parts of Aleppo province. The village is little more than 20 miles west of Aleppo, once Syria’s economic center.

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Survivors were reported still trapped in the rubble, al-Arabiya reported. Footage shot by Halab Today showed piles of debris where the mosque stood.

The attack came after a series of suicide attacks in Damascus Wednesday that killed 30 people. reported the airstrike occurred between 7 p.m. and 7:30 p.m., local time.

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The Syrian civil war began in March 2011. Since then, some 400,000 people have died in the fighting and more than a million injured. About half the country’s population has been displaced.

The Trump administration reportedly is considering sending 1,000 more troops to Syria in the fight against the Islamic State group. The Defense Department last week sent 2,500 troops to Kuwait to be on standby for possible deployment to either Syria or Iraq to augment the 1,700 troops already in Kuwait and Iraq.

Defense Secretary John Mattis made clear during his Senate confirmation hearings he wanted to accelerate the campaign against ISIS, which moved into Syria from Iraq as rebels attempted to oust Syrian President Bashar Assad.

Some 500, mostly Special Forces, troops currently are permitted in Syria and about 5,000 are in Iraq.

ISIS has been ousted from most of the territory it had captured in Syria and Iraq. Plans are being focused now on an effort to liberate Raqaa, ISIS’s de facto capital in Syria.