WASHINGTON — The United States military said that it had carried out an airstrike against a meeting of Qaeda militants on Thursday in Syria and that a number of the extremists had been killed.
The American military statement came as Syria activists reported that a mosque had been bombed and that scores of innocent civilians had been killed and wounded.
A spokesman for the United States Central Command said the American aircraft had struck a nearby building, but did not hit the mosque.
“We did not target any mosques,” said Col. John J. Thomas, a spokesman for the Central Command, which has responsibility for American military missions in the Middle East. “What we did target was destroyed. There is a mosque within 50 feet of that building that is still standing.”
But one local activist, Mohamed al Shaghel, said the people who had been struck had “no affiliation with any military faction or any political side.”
“I passed by the hospital,” he said. “I was told that about 50 were killed and 50 wounded. Rescuers are still looking for bodies under the rubble.”
The Syrian Observatory for Human Rights said the airstrike took place in Al Jinah, a village between the cities of Idlib and Aleppo. It said 42 people had been killed, most of them civilians, and described the attack as a “massacre.”
Local activists posted photos on Twitter of what appeared to be the fragments of an American-made Hellfire missile, suggesting that different types of aircraft were used in the attack. It could not be verified where the photo was take or if the fragment came from the attack.
While the American military said it had struck a legitimate target, Colonel Thomas said an investigation would be carried out to determine if innocent civilians had been killed or injured. He declined to say how many militants were estimated to have been killed.
Even as it has carried out a military campaign against the Islamic State for years, the United States has increasingly targeted Qaeda militants in Idlib Province.
During the waning hours of the Obama administration, a B-52 jet bombed what the Pentagon described as a Qaeda training camp, killing about 100 militants.
The Pentagon announced in January that it had carried out an airstrike that killed Mohammad Habib Boussadoun al-Tunisi, whom it described as a Qaeda leader tied to plots against the West.
In late February, an American strike in Idlib Province killed Abu al-Khayr al-Masri, the second-ranking Qaeda official.
Al Jinah is near the border shared by Aleppo and Idlib Provinces.
“U.S. forces conducted an airstrike on an Al Qaeda in Syria meeting location March 16 in Idlib, Syria,” the Central Command said in a statement. “Idlib has been a significant safe haven for Al Qaeda in recent years.”
Colonel Thomas said that it was a “precision strike,” which resulted in two large craters. A significant number of people were thought to have attended the meeting that was targeted.
There have been a number of friendly fire episodes in recent months. Late last month, Russian aircraft mistakenly bombed Syrian Arab fighters who were being trained by the United States. In a previous episode, Russian warplanes struck Turkish troops.
In September, the United States acknowledged that the American-led coalition had mistakenly struck Syrian government troops in the eastern province of Deir al-Zour. A military inquiry later concluded that the military officers who had planned the mission thought they were targeting Islamic State militants and that “unintentional” mistakes had led them to bomb Syrian forces.