Islamic State militants have killed 175 workers who were captured at a cement factory situated to the east of Damascus, Sputnik Arabic reported, citing its sources.

Reuters had earlier cited the Syrian military as saying that 175 workers from the Badiyah cement factory had been killed by Islamic State (IS, formerly ISIS/ISIL) militants.

However, the agency retracted its report shortly afterwards, saying that the sourcing on the story “was misattributed” and the report is “unconfirmed.”

Sputnik Arabic's sources said at least 75 plant workers managed to escape during the IS attack, while 175 others were reportedly killed.

On Thursday, Syrian SANA news agency reported a source in the Ministry of Industry who said that more than 300 Syrian civilians were missing following an Islamic State (IS, formerly ISIS/ISIL) attack on the Badiyah cement factory located outside Dmeir, about 50km to the east of the capital Damascus.

"The company has informed the officials that over 300 workers and contractors have been kidnapped by Islamic State militant group," the military source told the agency.

#ISIS kidnaps over 300 Syrian civilians after attacking factory near Damascus https://t.co/VZdd7JGckbpic.twitter.com/gL1qnkaVcN — RT (@RT_com) April 8, 2016

A factory administrator told AFP that the factory workers have been unreachable since Monday.

"We haven't been able to reach our family members since noon on Monday after an attack by Daesh [Arabic pejorative term for IS] on the factory. We have no information about where they are," a resident of the town of Dmeir said on Thursday.