Dozens of civilians were killed in attacks by Syrian regime and Russian forces on Sunday in Syria's Damascus suburbs, sources told Al Jazeera.

Ahmad, an officer from the Douma branch of the Syrian Civil Defense department, told Al Jazeera that regime air strikes and rocket barrages targeted Ghouta district in the Damascus suburbs.

"At least 41 civilians, including nine children, were killed in the attacks on Douma alone, another 250 have been injured," he said. "A school named al-Hosn al-Basri was targeted. The principal of the school along with four students were killed in the attack. Injured students have been taken to the nearest medical points."

"In the past three months, these areas have been constantly targeted by rocket attacks and air strikes, not one of those killed was a fighter - all of those killed were civilians," said Ahmad.

The UK-based Syrian Observatory for Human Rights put the death toll at 28 civilians killed, adding that the figure was likely to rise as many of the wounded were in critical condition.

'Massacres are happening'

Speaking to Al Jazeera, Douma-based photographer Muhammad al-Abdullah said he awoke to the sound of air strikes on Sunday morning.

"Most people are hiding in their cellars. Three air strikes landed next to my house. Massacres are happening here," Abdullah said.

Regime forces also targeted the nearby town of Saqba, also situated on the outskirts of Damascus, witnesses said.

The Syrian conflict - which began as a peaceful protest in March 2011 - has led to at least 250,000 deaths, according to the United Nations.

More than half of Syria's prewar population of 22.4 million have been internally displaced or have fled abroad.

PHOTO CAPTION

People insect a damaged area following airstrikes by forces loyal to the Syrian regime in the opposition-held area of Douma, outskirts of Damascus, Syria, 13 December 2015.

Al-Jazeera