Regime and jihadist fighters from the Islamic State of Iraq and Greater Syria (ISIS) have been fighting for control over the strategic gas field for three straight days.
The UK-based Syrian Observatory for Human Rights also confirmed the ongoing clashes, citing at least 270 people killed within the past three days.
"Violent clashes were continuing in and around the gas field...the deaths of 270 people killed in the fighting or executed [by the jihadists from ISIS have been documented]," reported the Observatory.
"A large majority of the men killed were executed at gunpoint after being taken prisoner following the takeover of the camp. Eleven of the dead were civilian employees, while the rest were security guards and National Defense Forces members," added Observatory director Rami Abdel Rahman.
Regime forces have been attempting to regain control of the field after ISIS seized control of Shaar Thursday in what the Observatory has described as the "biggest anti-regime operation by [ISIS]."
While jihadists have killed at least 60 regime troops, government forces have also killed at least 40 jihadist militants in their counteroffensive over the past three days as well, according to the Observatory.
