Airstrikes killed at least 23 civilians on Tuesday in one of the last pockets of Islamic State-controlled territory in Syria, according to Syrian state media and an opposition-linked monitoring group, as U.S.-backed forces in the area announced they have resumed their campaign against the extremists.

The Britain-based Syrian Observatory for Human Rights said it was not clear if the airstrikes in the Hassakeh province were carried out by the U.S.-led coalition or the Iraqi air force. It said the strikes killed 10 children, six women and seven elderly people. The state-run Syrian News Agency said 25 civilians were killed in the airstrikes south of the town of Shadadi, blaming the U.S-led coalition.

The strikes took place in an area where the U.S.-backed and Kurdish-led Syrian Democratic Forces are battling IS. (AP) APP/AFP