ISIS kidnapped 300 workers from a cement facility in Syria this week, and they remain unaccounted for.
Reuters reported that the workers were located in an area northeast of Damascus where the militants launched an assault against government forces this week, Syrian state television said on Thursday.
The workers and contractors of Al Badia Cement company were taken from near the town of Dumeir and their employer had lost all contact with them, state TV quoted the industry ministry as saying.
Fierce fighting broke out around Dumeir and the Dumeir military airport, 50 km (30 miles) northeast of the capital, late on Tuesday night after Islamic State militants launched attacks on government areas northeast of the capital.
Opposition sources in the rural eastern suburbs of Damascus said large parts of the town of Dumeir, which was already in the hands of squabbling rebel groups, were also captured by the militants who had fired at civilians protesting against their presence.
Hundreds of families had fled since the militant assault, the sources said.
The attacks on Tuesday and Wednesday included detonation of bomb-laden cars around the Dumeir military airport and an assault on the nearby Tishrin power station.
Syrian and allied forces backed by Russian air strikes this week forced Islamic State militants out of al-Qaryatain, which lies between Damascus and the ancient city of Palmyra, itself recaptured by the government last week.
The Britain-based Syrian Observatory for Human Rights, which monitors the five-year-old conflict, said on Wednesday contact had been lost with workers at the cement works but it was not known what had happened to them.