About 80 Daesh fighters have been killed since clashes broke out between the militants and Kurdish in northern Syria early Sunday morning, the Syrian Observatory for Human Rights told AFP.
The extremist group launched a major offensive on Monday against Kurdish-held villages in Raqqa and Hasakah provinces after President Barack Obama said the US-led coalition was intensifying its air campaign against the militants.
"We're intensifying our efforts against ISIL's base in Syria. Our airstrikes will continue to target the oil and gas facilities that fund so much of their operations," he said.
The Syrian Observatory for Human Rights said about 80 Daesh fighters had been killed since Sunday in the intensified airstrikes and fighting with Kurdish forces.
Kurdish forces regained control of more than 10 villages in Raqqa and Hasakah after they had been briefly overrun by the Daesh offensive, the Observatory told AFP
"The coalition aircraft have played an effective role in the recapture," Observatory chief Rami Abdel Rahman said.
Rahman added heavy fighting was continuing on Tuesday in several areas in the two provinces where Daesh was on the offensive, AFP reported.
