At least 39 people were killed on Saturday when air strikes targeted Syria's northern city of al-Raqqa, the de facto capital of the Islamic State group, a monitor group reported.
The dead include five children and seven women, said the Syrian Observatory for Human Rights.
The London-based watchdog group said the strikes targeted several areas in al-Raqqa, adding that there is no information yet whether the strikes were Syrian, Russian or US-led.
The death toll could likely rise as there were more than 60 people in critical condition, the Observatory added.
It said the strikes came a day after 16 people were killed by similar strikes on al-Raqqa.
