Damascus [Syria], March 21: A rocket attack killed 35 in a Damascus shopping district, in one of the deadliest rebel attacks on the Syrian capital, on Tuesday, as bombardment by the government and its allies left dozens of civilians dead in an opposition stronghold.

The state media said the opposition fire had hit the area of Jaramana, which residents said was full of shoppers, as many were buying presents before Mother's Day in Syria, on March 21.

Tuesday's attack followed a heavy bombardment in the shrinking rebel enclave of Eastern Ghouta, which is east of the capital, and killed 38 civilians.

Rebel groups have stepped up artillery attacks since pro-government forces launched a major air and ground assault on the Eastern Ghouta a month ago.

Eastern Ghouta, which houses around 400,000 residents, has remained under a crippling regime siege for the last five years with humanitarian access being completely cut off.

In May last year, Russia, Iran and Turkey signed an agreement to set up de-escalation zones, in order to prevent airstrike-related incidents in some parts of Syria. The de-escalation zones include - Idlib province, some parts of Latakia province, Hama and Aleppo provinces, Homs, Eastern Ghouta, Daraa and al-Quneitra provinces in southern Syria.

Syria has been embroiled in a civil war since 2011. Protesters have been long demanding the resignation of President Bashar al-Assad over his autocratic rule.