Syrian opposition activists said around 40 people, mostly civilians, were killed in a mosque in the area, accusing the US -led coalition of carrying out the airstrike Thursday evening.
The attack happened as the mosque was full of worshippers during evening prayer, the Syrian Observatory for Human Rights said.
The US said it had carried out an air strike, killing several al-Qaeda militants, but had not hit a mosque.
An American official acknowledged to AFP that the decimated mosque was just 50 feet from the Al Qaeda target, but claimed the us has photographic evidence that the mosque was intact after the American strikes. He put the death toll at 56. The photo, which the military said was taken less than five minutes after the strike, showed extensive damage to the building.
The US has been bombing jihadists in war-torn Syria as part of an global coalition since 2014.
Civil defense official Yahya Javad said the attack also wounded dozens of others in the city's Al-Etarip area.
Ahrar al-Sham, a hardline Islamist group that has fought alongside nationalist factions under the banner of the Free Syrian Army, has been involved in clashes this year with jihadist groups that Washington has targeted.
He told CBS News correspondent David Martin there was a mosque across the street from the building the USA hit. The bombing occurred during prayer time.
More than 320,000 people have been killed in Syria since the conflict with anti-government protests six years ago.
Turkey and the United States support the main opposition forces, while Russian Federation and Iran back Assad's government.
First responders and local activists said at least 35 people were killed.
The Syrian and Russian military have carried out many air strikes in Idlib and Aleppo provinces during the war.
Thomas later clarified that the precise location of the strike is unclear and added, "We are going to look into any allegations of civilian casualties in relation to this strike". Monitoring groups say the number is much higher.