Fighting persists in Islamic holy month of fasting, with many women and children among the dead.
Hundreds of civilians have been killed in both Syrian government and rebel attacks across the wartorn country in recent days, according to local activist groups.
More than 180 civilians have been killed across Syria since Friday, including 22 children and 23 women, the Local Coordination Committees, a grassroots network of activists, said on Sunday.
At least 90 people were killed on Friday, while a further 83 civilian deaths were recorded by Saturday night. Most of them occurred in the Aleppo province.
“Even with the deadly standards of this war, these death tolls are staggering,” Al Jazeera’s Reza Sayah, reporting from Gaziantep on the Turkish side of the Syria-Turkey border, said.
The UK-based Syrian Observatory for Human Rights (SOHR), which records daily developments in Syria, also released figures on Sunday detailing the killing of at least 327 civilians, including 76 children and 41 women, in Aleppo over the past 15 days.
More than 100 of the 327 were reportedly killed in bombing by government warplanes, while 126 were killed in attacks by opposition fighters on government-held areas in Aleppo.
In the suburbs of the city, another 94 were killed by Syrian regime bombardments, according to the SOHR.
Zouhir al-Shimale, a local journalist in Aleppo, said the attacks have not stopped since the rebels opened the strategically important Ramosa route a week ago.
“The shelling on the city has intensified. The regime has been attacking the city’s main roads that people have been using to get around eastern Aleppo,” Shimale told Al Jazeera on Sunday.
“Yesterday, the regime used cluster bombs, which they have been using extensively recently, to attack a bus station in al-Firdous neighbourhood, whereby more than 50 civilians, including women and children, were attempting to leave the city. Most of them were killed.”
Once Syria’s largest city, Aleppo has been divided between regime forces in the western part of the city and rebel groups in the east, for four years.
Forces loyal to Syrian President Bashar al-Assad imposed a weeks-long siege on the rebel-held eastern half of the city last month, until opposition forces announced they had broken the siege a week ago.
“It was one week ago today, when rebel forces broke through the government siege of Aleppo. These rising death tolls could be an indication of the government fighting back and retaliating,” Al Jazeera’s Sayah said.
Elsewhere, opposition activists in the rebel-held town of Daraya on the suburbs of Damascus accused the Syrian government of dropping barrel bombs containing napalm – an incendiary weapon made up of both fuel and a gel substance.
According to opposition activists, “government forces and helicopters have dropped about 12 [barrel bombs] today and another 24 yesterday”, killing one person and injuring others, Sayah said on Sunday.
The use of napalm against civilian targets, and in areas densely populated with civilians, has been prohibited by the United Nations. The chemical is very flammable and difficult to remove from the skin.
“Both sides have used chemical weapons, according to rights groups,” said Sayah.
“Unfortunately no one has been held accountable – which probably has to do with the difficulty of getting access to these areas.”
Approximately 8,000 Syrian civilians are living in Daraya, which has been under siege by government forces since 2012.
The Syrian conflict, which began with peaceful protests in March 2011 against Assad, has spiralled into a multi-sided civil war.
According to UN estimates, more than 280,000 people have been killed in the conflict so far.