The bombing also destroyed civilian property and wounded several people, some of them critically, the Britain-based Observatory added.
President Bashar al-Assad's air force has carried out near-daily strikes against areas under rebel control in the northern province since last December, killing several hundred people, mostly civilians.
Rights groups have repeatedly criticised the use of barrel bombs, which they say fail to discriminate between civilian and military targets.
In July, Human Rights Watch accused the regime of defying a UN Security Council resolution ordering all sides in Syria's war to stop indiscriminate attacks.
Syria's multi-front war began as a peaceful movement demanding democratic change, but morphed into an all-out civil war after Assad's regime unleashed a brutal crackdown against dissent.
More than 180,000 people have been killed since March 2011, and nearly half the population have fled their homes.
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President Bashar al-Assad's air force has carried out near-daily strikes against areas under rebel control in the northern province since last December, killing several hundred people, mostly civilians.
Rights groups have repeatedly criticised the use of barrel bombs, which they say fail to discriminate between civilian and military targets.
In July, Human Rights Watch accused the regime of defying a UN Security Council resolution ordering all sides in Syria's war to stop indiscriminate attacks.
Syria's multi-front war began as a peaceful movement demanding democratic change, but morphed into an all-out civil war after Assad's regime unleashed a brutal crackdown against dissent.
More than 180,000 people have been killed since March 2011, and nearly half the population have fled their homes.
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