Rebel groups and government forces are locked in a cycle of attacks around Damascus and in the rebel-held enclave of Eastern Ghouta
The United Nations on Sunday called on Syria's warring sides to stop targeting civilians in the capital Damascus and nearby neighbourhoods, where escalating bombardment has killed dozens in recent days.
Rebel groups and government forces are locked in a cycle of tit-for-tat attacks around Damascus and in the opposition-held enclave of Eastern Ghouta.
On Sunday, UN coordinator for humanitarian and development affairs in Syria Ali al-Zaatari called on "all warring sides to avoid targeting civilians".
"For days, there have been daily reports about civilians being killed and others being severely wounded, in addition to warehouses, hospitals and schools being put out of service during the exchange of shellfire, particularly in Damascus and Eastern Ghouta," Zaatari said.
His comments in Arabic came in a statement emailed to AFP.
Government forces have escalated their bombardment of Eastern Ghouta, an opposition stronghold outside Damascus, since hardline rebel group Ahrar al-Sham attacked a military base in the area last week.
Since Tuesday, heavy artillery fire and air strikes on Eastern Ghouta have killed at least 66 civilians including 13 children, according to the Syrian Observatory for Human Rights.
At least 281 people have been wounded, the Britain-based monitor said on Sunday.
Rebel groups meanwhile have fired rockets into Damascus neighbourhoods, killing at least 16 people since Thursday, the Observatory said.
The toll included two people killed by rocket fire on Sunday.
"The United Nations hopes for an immediate ceasefire and the establishment of secure humanitarian corridors to evacuate wounded, sick, and elderly people, as well as children, as soon as possible from areas seeing hostile operations," Zaatari said.
He called for the delivery of humanitarian assistance to those who need it across the country.
Eastern Ghouta is supposed to be part of a "de-escalation zone" under a deal between Russia, Iran and Turkey aimed at reducing the level of violence.
President Bashar al-Assad's forces have besieged Eastern Ghouta since 2013, making humanitarian conditions in the area, where some 400,000 people live, extremely dire.