At least 26 people including seven children were killed and more than 100 wounded in Syrian government air strikes near the capital Damascus today, a monitor said.
The raids on the town of Douma, northeast of the capital, came as the conflict entered its fifth year and the death toll soared to more than 215,000.
The Syrian Observatory for Human Rights said government warplanes had carried out several raids on Douma.
The Britain-based monitor said the toll could rise because of serious injuries among the wounded. Earlier, it gave a toll of 18 dead in the attacks.
An AFP photographer on the ground said residents were sheltering in basements, terrified of the ongoing bombardment.
Douma lies in the opposition bastion area of Eastern Ghouta, which has been subject to massive regime aerial bombardment for months.
The area has also been under a crippling government siege for nearly two years as part of a regime attempt to break the rebel hold in the region.
Rebels regularly fire missiles into the capital from the area.
Today was the fourth anniversary of Syria’s conflict, which began with anti-regime protests in mid-March 2011 and spiralled into a bloody war after a harsh government crackdown on demonstrators.
The Observatory said today that at least 215,518 people have since been killed in the conflict.