BEIRUT — The United States struck an al-Qaida gathering in northern Syria killing dozens of militants, and is investigating reports that civilians were killed, U.S. officials said Friday.
Syrian opposition activists said around 40 people, mostly civilians, were killed in a mosque in the area, accusing the U.S.-led coalition of carrying out the airstrike Thursday evening.
Friday prayers were cancelled across rebel-held parts of northern Syria Friday after the airstrike that opposition activists and paramedics said struck the crowded Omar Ibn al-Khattab Mosque in the Jeeneh district in Aleppo province, killing and wounding dozens of people, some of whom were left trapped under the rubble.
U.S. Army Maj. Josh Jacques, a U.S. Central Command spokesman, said the U.S. did not target or strike a mosque.
"We targeted an al-Qaeda gathering across the street from a mosque. The mosque does not appear to be damaged following the strike," he said, adding: "We are aware of the reports of civilian casualties and we are looking into it."
Navy Capt. Jeff Davis, a Pentagon spokesman, said, "we are not aware of any credible assessment of civilian casualties."
He showed reporters a U.S. military photo of the strike and said that "dozens" of al-Qaida militants who were meeting in the building were targeted and killed. The photo showed extensive damage to the building, and debris scattered toward the mosque, but little visible damage to the mosque or two cars parked next to it.
He said the U.S. was aware the mosque was next door and deliberately did not strike it. He said that some video he has seen showed damage to the building on the other side of the al-Qaida base.
Davis said the U.S. believes there were some high ranking individuals there, but he did not identify them, and said the U.S. is still assessing the results of the strike. He said al-Qaida had been using the building as a meeting place, but he said he did not know if the building had at some point been associated with the mosque next door.
He said that manned and unmanned aircraft launched airstrikes at the building, which would include Hellfire missiles and bombs.
A powerful Syrian opposition group and other opposition activists blamed the U.S.-led coalition for the airstrike. The coalition has been targeting the Islamic State group and al-Qaida's affiliate in northern Syria for more than two years, but it was not clear how the opposition group knew who carried out the strike. Russian and Syrian aircraft are known also to operate in the opposition-held region.
Russian Foreign Ministry spokeswoman Maria Zakharova said fragments of ammunition with Latin markings were found in the debris at the scene, which made it possible to conclude that Hellfire missiles were being used.
"The US military has officially confirmed that it was they who struck the area. The goal was a building located across the street from the mosque, which was used to hold meetings by al-Qaida terrorists," she said.
Bahaa al-Halaby, an Aleppo-based opposition activist based, said the Thursday night airstrike hit as about 250 people had gathered at the mosque for prayers or to attend a religious lesson. Mosques are usually crowded on Thursday night ahead of Friday, the day of communal prayers in the Muslim weekend.
"This was one of the worst massacres committed in the area," al-Halaby said.
An Islamic networking group as Advocacy and Intimation is known to be active at the mosque where religious lessons are offered to the local population, according to al-Halaby and the Britain-based Syrian Observatory for Human Rights, which also described the attack as a "massacre."
Jihadi and militant websites said the group, which aims to encourage people to adhere to Islam by peaceful means, was holding a weekly meeting with about 250 people in attendance. The group has branches in other countries.
Footage from the scene showed volunteers putting out fires and pulling victims from the rubble.
The Observatory and al-Halaby said Friday prayers were cancelled in rebel-held parts of Aleppo and Idlib provinces, adding that such decisions are not uncommon where mosques have been targeted in the past.
The Observatory said the airstrike on the mosque in Jeeneh killed 46 while the Local Coordination Committees, another monitoring group, said 40 were killed. Such discrepancies are not uncommon in the immediate aftermath of attacks in Syria.
The powerful ultraconservative Ahrar al-Sham group also said the airstrike was carried out by the U.S.-led coalition, adding that "the targeting mosques and places of worship is a war crime."
Baldor reported from Washington. Associated Press writer Jim Heintz contributed reporting from Moscow.