The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) has released most of the cement workers it kidnapped on Thursday, a monitoring group said.

It was still unclear how many were being held and how many of the kidnapped Al-Badia cement factory workers were freed - sources told Al Jazeera  that the number was far less than 300 - but ISIL's Amaq website said the armed group had released nearly 300 workers.

It also said that the group executed four workers for being from the Druze minority and would not release 20 men accused of belonging to a pro-government forces.

Local officials in two nearby towns secured an agreement for ISIL to release the workers, kidnapped from the plant located near the town of Dumayr, the UK-based Syrian Observatory for Human Rights said.

The monitoring group said that around 170 workers were freed after others had already managed to escape.

A military source the told AFP news agency that he saw dozens of cement workers arrive on Friday evening at a nearby regime-held military airport.

READ MORE: 'Mass grave discovered' in Syria's recaptured Palmyra


Syrian state television said ISIL had kidnapped 300 workers and contractors. The Observatory said 140 workers had fled before the fighters arrived.

ISIL's latest attacks near Damascus are seen as retaliation for military setbacks suffered by the group elsewhere in Syria.

Last month, Syrian regime forces - backed by Russian warplanes - drove ISIL from the strategic and ancient city of Palmyra, which the fighters had controlled for 10 months.

Source: Al Jazeera and agencies