Photo taken on March 20, 2018 shows the site of a rocket attack east of Damascus, capital of Syria. The death toll rose to 35 in a rebel rocket attack on a crowded marketplace Tuesday east of Damascus. (Xinhua)

DAMASCUS, March 20 (Xinhua) -- The death toll rose to 35 in a rebel rocket attack on a crowded marketplace Tuesday east of the Syrian capital Damascus.

The improvised rocket hit the Kashkoul marketplace east of Damascus, leaving many more people wounded.

The attack is one of the deadliest caused by rebels' rocket fire in Damascus, where four other people were killed Tuesday by mortar shells in other parts of the capital city.

This comes as the Syrian army is advancing in the depth of the rebel bastions in Eastern Ghouta in the countryside of Damascus.

The state TV said the Syrian forces reached on Tuesday the farmlands of the Ayn Tarma area, a key bastion of the Failaq al-Rahman rebels, who are responsible for most of the mortar and rocket attacks on the capital.

The Syrian army has already controlled over 80 percent of Eastern Ghouta, the last remaining threat to the capital.