The Pentagon said it carried out an airstrike against al-Qaida in Syria, but denied hitting a mosque where a human rights group said more than 40 people were killed.
Manned and unmanned aircraft targeted a building next to the mosque in the town of al-Jinah, near Aleppo, a Pentagon spokesman told reporters Friday. The spokesman, Navy Captain Jeff Davis, said the strike killed dozens of "core al-Qaida" senior members who were meeting inside the building Thursday.
The Pentagon released a photo of the strike's aftermath to support its claims. The photo showed what appears to be an intact, undamaged mosque next to a larger building that apparently suffered multiple weapons strikes. Debris was scattered on the street, but many cars parked between the mosque and the heavily damaged building were intact.
"The area was extensively surveilled prior to the strike in order to minimize civilian casualties," Davis said.
Air Force Colonel John Thomas, a spokesman for U.S. Central Command, which oversees military operations in the Middle East, said the U.S. military would investigate "any allegations of civilian casualties in relation to this strike."
"We take this very seriously," he added.
An earlier account from another Central Command official estimated the mosque was about 15 meters from the separate building that came under attack.
Earlier, the Syrian Observatory for Human Rights said at least 42 people were killed and dozens more wounded in an airstrike on the mosque in northern Syria. The group said it was unable to determine whose warplanes carried out the attack.
Syrian and Russian military aircraft are known to have been active in that area of northern Syria.
"More than 100 people were wounded," Syrian Observatory head Rami Abdel Rahman said, adding that many were still trapped under rubble. Rahman's group is based in Britain, and compiles its reports based on descriptions from sources on the ground in conflict areas.
The town of al-Jinah has been known to be under the control of Islamist groups, but the Syrian Observatory said no militant factions were present at the time of the airstrike.
Thursday's attack targeting senior al-Qaida members followed suicide attacks a day earlier in the Syrian capital, Damascus, that killed at least 30 people on the sixth anniversary of the start of the Syrian civil war.
Since 2011, the conflict in Syria has killed 400,000 people, wounded more than 1 million and displaced half the country's population.