The report has not been officially corroborated.
The militants had taken over the massive plant near Damascus on Tuesday and Wednesday.
Amaq reported that workers were released after being investigated and found to be Muslim and not members of the Syrian regime. But 20 people believed to be part of regime militias were still in custody, and four others were executed for being from the Druze sect, according to the report.
Ramdi Abdulrahman, head of the London-based Syrian Observatory for Human Rights, told CNN on Friday that prominent figures from nearby towns secured an agreement for the release of 170 workers of more than 300 workers. He could not confirm the report from Amaq.
Al-Badiyeh Cement Co. had said the militants were holding hundreds of workers and contractors, according to the state-run Syrian Arab News Agency, citing a source in Syria's Ministry of Industry.
Local official Nadim Kreizan told SANA that witnesses saw about 125 "abducted workers" being put on buses headed toward areas more firmly under ISIS
Abdulrahman had earlier said he believed 150 to 250 factory employees were missing. The observatory later said that at least 140 employees of the factory were able to escape during the attack, while no fewer than 170 were captured.
The factory is in Al-Dhmeir, a town 48 kilometers
(about 30 miles) northeast of Damascus, the Syrian capital and the base of President Bashar al-Assad
Envoy: Peace talks to resume next week
Civilians have been caught in the middle of Syria's 5-year-long civil war
. ISIS has been accused of committing atrocities such as systematic rapes, killings
, and using Syrians as human shields
The conflict has left more than 250,000 people dead, more than 1 million injured and
more than 11 million displaced in and outside the country, according to the United Nations
Key parties in the fighting are scheduled to take part in resumed peace talks next week in Geneva, Switzerland, said Staffan de Mistura, the U.N. envoy to Syria. ISIS and al Qaeda-affiliated al Nusra Front are not part of the talks.
Talking to reporters Thursday, de Mistura said negotiations should begin as soon as Monday. Syrian government officials may not arrive in Geneva until Thursday or April 15 after parliamentary elections, and the U.N. envoy downplayed the significance of their absence, noting that these "proximity talks" don't involve all players sitting face to face in the same room.
De Mistura spoke of pushing toward a "political transition" in Syria
, a change that Western governments and Syrian rebels have championed.
Assad has steadfastly refused to step down as President, but he's opened the door to having opposition figures in the government