The Islamic State on Sunday launched counterattack on the U.S.-led forces near Tabqa city, taking advantage of a sand storm sweeping the northeastern province of Raqqa.
ISIS fighters attacked bastions of the Syrian Democratic Forces in the villages of Ayed al-Kabir, Jlaib Aby Jaber and Ajeel near the military airport of Tabqa.
Pro-ISIS news feeds said 15 SDF fighters killed in the attacks.
Meanwhile, thousands of civilians in ISIS-held areas in eastern Raqqa province have been under severe siege as the daily clashes between the radical group and U.S-allied forces mount.
Muhab Nasser, said thousands of people are stuck in the town of Tabqa. They are trapped within an area of 20 km2, having no way to escape the SDF bombing and the U.S.-led coalition airstrikes that killed hundreds of people in the last months, he added.
No water or power supply is available since 28 days amid lack in medical equipment and basic food staples.
The SDF, an alliance made up of Syrian Kurdish and Arab fighting groups, launched the fourth phase of their offensive last Thursday.
The multi-phased campaign by SDF was launched in November and aims ultimately to drive the jihadists from Raqqa, their de facto Syrian capital
