Syrian regime shelling killed four schoolchildren and a man on Tuesday in the rebel-held besieged town of Jisreen east of the capital Damascus, a Britain-based monitor and a medical source said.

"A shell fired by regime troops hit the entrance of a school in Jisreen just as children were leaving it, killing five people including four schoolchildren," Syrian Observatory for Human Rights chief Rami Abdel Rahman said.

A medical source at the town hospital confirmed the death toll.

An AFP photographer at the medical facility saw the bodies of four children, as well as school bags and a small shoe covered in blood.

He also saw several wounded, including one child with amputated legs.

A man cried out after learning his son had died, as others around him tried to comfort him. 

Jisreen lies in the rebel-held stronghold of Eastern Ghouta east the capital, where opposition fighters have been battling President Bashar al-Assad's troops for six years.

On July 22, the regime announced a ceasefire with rebels in the besieged area, which was included in a so-called "de-escalation zone" agreed by rebel backer Turkey and government allies Russia and Iran.

But regime shelling on the area has been on the rise for the past week.

Tuesday's shelling comes as Eastern Ghouta is also facing a mounting humanitarian crisis.

Shocking AFP images from the region this month showed severely underweight children, and doctors reported two infants had died of malnutrition and related complications.

On Monday, dozens of trucks carrying aid for 40,000 people entered Eastern Ghouta.

Source: AFP