Syria regime air strikes and artillery fire pounded areas held by the Islamic State group in the south of Damascus on Thursday, official media and a war monitor said. "There are also reports of civilian casualties".
Reports were from sources on the ground, noting that airstrikes had picked up on what remained of the Palestinian refugee camp of Yarmouk and the nearby Hajar Al-Aswad.
The security team was supposed to give the all-clear for OPCW inspectors to follow, but their visit was put on hold pending the security situation, Uzumcu added.
Assad is in his strongest place since early within the seven-year warfare regardless of US, British and French air strikes on April 14 - their first coordinated motion within the warfare.
Assad is accelerating his campaign to retake the remaining enclaves his forces encircle around Syria, which would leave rebels with only their two major strongholds in the northwest and southwest. The suspected poison gas attack creates a conundrum for Western powers, who are determined to punish Assad for using chemical weapons but have no strategy for the sort of sustained intervention that might damage him.
But the single volley of air strikes, hitting three targets far from any front line, had no effect on the wider war which has killed almost 500,000 people and made more than half of Syrians homeless.
The camp was home to some 160,000 Palestinians before the Syrian conflict began in 2011, refugees from the 1948 war of Israel's founding, and their descendents.More news: Virat Kohli, De Kock on the Attack in Big Chase
Meanwhile, US Defense Secretary Jim Mattis has said that the Syrian government is responsible for delays in inspectors reaching sites of a suspected chemical weapons attack.
Syria and its ally Russian Federation deny utilizing chemical weapons within the assault on Douma.
Syrian state media say hundreds of rebels fighters in a town northeast of Damascus have handed in their weapons and started to leave under an evacuation deal.
Thousands of civilians, including the fighters' families, are expected to leave with them for northern Syria before the areas come back under Assad's rule under deals similar to others carried out across the country as government forces advance.
The area is much smaller than the eastern Ghouta region that Syrian government forces recently recovered in a Russian-backed offensive.
They hold pockets in Deir Ezzor and have a presence in Syria s vast Badia desert. Although most residents have fled, up to 12,000 remain there and in the neighbouring areas under jihadist or rebel control, said the United Nations agency that helps them.
"The military operation against IS in the south of Damascus has started after the failure of negotiations to evacuate" the jihadists from the area, Observatory chief Rami Abdel Rahman said.