The Syrian military has reportedly attacked the besieged, rebel-held town of Darayya, dropping about thirty crudely-made bombs on it from helicopters.
This came just hours after the government had finally allowed the United Nations to make a food aid delivery to the area - the first for four years.
Reports from Darayya suggest the bombing had hampered the distribution of the desperately needed supplies.
Overnight, trucks carrying medicine, food and flour reached the town.
Meanwhile Kurdish-led forces said they had encircled a stronghold of Islamic State (IS) in northern Syria.
The Syrian Democratic Forces (SDF) said they had cut off the road between Manbij and Bab, north-east of Aleppo.
The US-backed offensive aims to expel IS militants from the region to the north of the group's de facto capital, Raqqa.
Earlier, the UN said its aid delivery had provided food rations including rice, lentils, sugar and oil for 2,400 people as well as wheat flour for all the estimated 4,000 people in the town.
The convoy also contained 1.9 tonnes of medicines, antibiotics and vitamins, the World Health Organisation (WHO) said.
However, burns kits to treat about 30 people with dressings and painkillers could not be delivered as they were rejected by the government, the WHO said.
The supplies are thought to be enough to last the besieged population a month.
"We are hoping that this will lead to a much more sustained, durable access to Darayya and other besieged areas in Syria," said Jens Laerke, a UN spokesman.
He said there were about 4.6 million Syrians living in besieged and hard-to-reach areas who were in need of supplies.
Rebel-held Darayya, which is surrounded by government forces, was among the first to report protests against President Bashar al-Assad's government.
On Thursday the UN's special envoy for Syria, Staffan de Mistura, said the Syrian government had given permission for aid to be delivered to 19 areas designated as "besieged" in the country, where an estimated 600,000 people live.
The US, UK and France have called for air drops of aid and Mr de Mistura said he believed this pressure had led the Syrian government to allow aid to enter besieged rebel-held areas.