A spokesman for the Kurdish Democratic Union Party (PYD) said YPG forces had taken over "a very large cement factory" in Raqqa province.
"The YPG have been trying to take this area for a long time," Newaf Khalil said.
The so-called Syrian Observatory for Human Rights, also reported the event, saying that Kurdish People's Protection Units (YPG) "took over a large cement factory and three villages" Northwest of the town of Ain Issa.
Rami Abdel Rahman, Head of the Britain-based Observatory, said the YPG had fought "fierce clashes" against ISIL terrorists in the past 48 hours and were now in control of a total of villages in the area.
At least six ISIL fighters had been killed in Sunday's clashes, bringing to 20 the death toll for the Takfiri group during the past two days, he said.
There was no immediate information on Kurdish casualties.
Ain Issa is less than 60 kilometers (35 miles) from Raqqa city.
It also lies just 45 kilometers South of Tal Abyad, a border town used by ISIL as a gateway for terrorists coming in from Turkey.
Syria has been grappling with a deadly crisis since March 2011. The violence fuelled by Takfiri groups has so far claimed the lives of over 210,000 people, according to reports. New figures show that over 76,000 people, including thousands of children, lost their lives in Syria last year.
Over 3.8 million Syrians have left their country since the beginning of the crisis. According to reports, more than seven million Syrians have become internally displaced.
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