The bombs targeted the green belt of Ghouta around the capital and markets in the city of Douma, about 10 km (6 miles) northeast of central Damascus, the Britain-based Syrian Observatory for Human Rights said.
Syrian officials were not available to comment.
Rockets fired on Tuesday from Ghouta killed at least 10 people in Damascus. The group behind that attack, Islam Army, said it was in revenge for Syrian army bombing of civilian areas.
On Tuesday many of the wounded were taken from the rubble of flattened buildings to medical centers, the Observatory said.
One barrel bomb attack by Syrian forces last Thursday in a Ghouta market killed at least 40 people, the Observatory said.
Syrian President Bashar al-Assad said in an interview broadcast on Tuesday that the Syrian air force did not use barrel bombs, which are containers packed with explosives and projectiles that are dropped from helicopters.
