BEIRUT -- A Syrian rights group reported Monday that the death toll of civilians purportedly killed in airstrikes by the U.S.-led coalition on a village controlled by the Islamic State group in Syria has risen to 64, including 31 children, as the U.S. military said it is assessing whether to launch a formal investigation into the claim.

U.S. Army Col. Steve Warren, a Pentagon spokesman, said that so far there was no information to indicate there were civilians present in the village. He said U.S. Central Command is assessing the claims of civilian deaths in order to determine if a formal investigation should be opened.

Earlier, U.S. Central Command spokesman Maj. Curtis Kellogg said there was no indication that any civilians were killed in the airstrikes Thursday night on the northern Syrian village of Bir Mahli.

Warren said the aircraft targeted 50 Islamic State fighters and their camp. Kellogg said a vehicle was also hit.

But the Britain-based based Syrian Observatory for Human Rights, which first reported the civilian deaths, said Monday at least 64 civilians were killed in the airstrikes on the remote village near the border city of Kobani.

Observatory director Rami Abdurrahman said the dead include 16 girls and 15 boys, as well as 19 women. He said the airstrikes hit civilians, all of them Arabs, in their homes. The Observatory relies on a network of activists on the ground inside Syria.

It was not immediately possible to independently verify the conflicting reports in the village.

Two videos and several photos purporting to show the aftermath of the strikes on the mixed Arab and Kurdish village were mostly produced by the Islamic State group's media arms. In one video released by the pro-ISIS Aamaq News Agency, a man walks between children allegedly wounded in the airstrikes.

Kurdish fighters, backed by coalition airstrikes, pushed the ISIS militants out of Kobani earlier this year. But the extremist group still controls other nearby villages and has continued to battle the largely Kurdish opposition in the area.

Kellogg said that prior to the airstrikes, Kurdish forces in the area said the village has been emptied of civilians for at least two weeks.

Shorsh Hassan, a spokesman in Kobani for the main Kurdish militia known as the People's Protection Units had earlier told The Associated Press that Bir Mahli was emptied of civilians.