Opposition groups and regime 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.
Zaatari's appeal came as a military source said the Syrian army and loyalist militiamen retook full control of Albu Kamal from Daesh, ousting the terrorists from their last urban stronghold in Syria.
Regime forces have escalated their bombardment of Eastern Ghouta, an opposition stronghold outside Damascus, since 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.