The U.S. Central Command said Saturday that it was investigating claims that a U.S.-led airstrike in northern Syria killed at least 52 civilians, including seven children.
U.S. Army Major Curt Kellogg said authorities were seeking information to corroborate the casualties, first reported by the Syrian Observatory for Human Rights, a British-based monitoring group . The group also reported 13 others missing.
Observatory director Rami Abdel Rahman said the strikes on the Aleppo provincial village of Bir Mahli occurred early Friday, as Syrian rebels and Kurdish militiamen battled Islamic State jihadists nearby. He said the death toll was the highest civilian loss in a single attack by U.S. and Arab forces since they started air raids against hard-line Islamist militant groups in Syria such as Islamic State.
U.S.-led forces are also targeting the group in Iraq.
The strikes had killed at least 66 civilians in Syria from the start of the raids on September 23 until Friday's attack, which brought the total to at least 118. The campaign has also killed nearly 2,000 Islamic State fighters, the observatory said.
Airstrikes by the U.S.-led coalition have supported Kurdish militias battling extremists in Aleppo province, particularly in and near the flashpoint town of Kobani, located near the Turkish border and near Bir Mahli.
Backed by coalition airstrikes, Kurdish fighters drove IS extremists from Kobani in January.
The airstrikes have slowed Islamic State advances but have failed to weaken the militants in areas they control. The group has built its own government in Syria's city of Raqqa, where it is most powerful.
Some information for this report came from Reuters.