More than 300 workers have been abducted by the Islamic State terrorist militia from a cement factory near Damascus, Syria's state television reported on Thursday.
The abduction was confirmed by managers of the factory located near the town of al-Dumeir northeast of Damascus, the broadcaster reported, citing an unnamed official at Syria's Industry Ministry.
"The company informed the ministry that it has not been able so far to communicate with any of the abductees," the broadcaster quoted the official as saying.
The report did not say when the alleged abductions occurred.
Residents in the nearby area of Giraud saw Islamic State vehicles carrying nearly 125 workers and heading to the militant-held town of Tel Dkoh on the edge of the eastern Ghotta region, local official Nadeem Krizan told Syria's official news agency SANA.
However, the official did not account for the other workers reportedly seized by Islamic State.
The Syrian Observatory for Human Rights, which relies on a network of activists inside Syria, earlier said that 150 to 250 workers had gone missing since Islamic State launched an attack on the factory on Tuesday.
The Britain-based watchdog added that the attack on al-Dumeir has so far killed at least 20 Syrian soldiers and allied paramilitaries on the 48 hours.
On the ground late Thursday, the jihadist group lost a key crossing point with Turkey: the Al Rai village in the northeastern outskirts of Aleppo, the Observatory said.
"This is the last passageway for the Islamic State with the outside world," the head of the Observatory, Rami Abdel Rahman told dpa.
"The jihadists still control a small crossing further east, in the town of Halwaniyeh, but this is only used by their high-ranking commanders. The one they lost is usually used to smuggle jihadists into Syria," Rahman said.
Islamic State's latest attacks near Damascus are seen as retaliation for the military setbacks suffered by the al-Qaeda splinter group elsewhere in Syria.
Last month, Syrian regime forces, backed by Russian warplanes, ended Islamic State's 10-month grip on the ancient city of Palmyra.
On Sunday, Syrian forces recaptured the town of al-Qaraytain, about 100 kilometres south-west of Palmyra, from Islamic State.
Islamic State and al-Qaeda's Syria branch, al-Nusra Front, are excluded from a major US-Russian-brokered ceasefire in Syria, implemented in February, that is aimed at boosting indirect peace talks between the Syrian government and the opposition.
A new round of the UN-sponsored talks is expected to start in Geneva next week.
UN mediator Staffan de Mistura said Thursday that he would open a dialogue with regional powers supporting different sides in the Syrian war ahead of the new talks, to find out if they support a political transition in Syria.
In the coming days, De Mistura plans to travel to Iran and Syria and to meet Turkish and Saudi officials in Europe, ahead of the round of indirect peace talks that are now expected to start on Wednesday.
The UN Syria envoy clarified that he has not asked to see President Bashar al-Assad in Damascus but plans to meet Foreign Minister Walid al-Moallem.
Syria's partial ceasefire is also aimed at letting relief aid into Syrian towns besieged by regime forces and rebels.
UN envoy Jan Egeland said that the Syrian government has blocked deliveries of international aid to beleaguered areas in the past days, warning that the slowdown of humanitarian efforts can hurt the peace process.
Government authorities denied passage to four convoys that would bring aid to some 300,000 people in cities besieged by the army, he said, adding that opposition fighters blocked one Red Crescent aid delivery.
"I'm disappointed, I am disheartened of what we achieved over the last week," said Egeland, who chairs a task force of global and regional powers that are supposed to negotiate humanitarian access with the conflict parties.
The medical charity group Doctors Without Borders (MSF) has warned that the humanitarian situation remains dire in Syria.
"Over the past two weeks in the besieged areas in the Damascus region a doctor has been shot dead by a sniper, two of the field hospitals we support have been bombed, besieged neighbourhoods continue to be shelled, and medical aid is still blocked or restricted," Bart Janssens, the MSF director of operations, said in a statement.