Syrian government helicopters have dropped barrel bombs on opposition-held districts of the northern city of Aleppo, killing at least 60 people, including several children, and injuring dozens, Al Jazeera reported.
Most of the victims apparently died in a popular market in the al-Sukari district. Opposition activists say the market was packed with residents waiting to get food aid at a distribution centre.
Two bombs hit Sukari minutes apart, with the second catching helpers who had gone to the assistance of people injured in the first.
"We were sleeping safely when the first barrel dropped around midnight," resident Abu Mohammad told news agency AFP.
"And when people came to the rescue, a second barrel dropped, so all those people who were on the site were dead.
"We don't have military bases in our area. All people here are civilians," he said.
The other bomb hit Aleppo's Ashrafiyeh neighbourhood.
Syria's regime has waged a fierce aerial offensive against rebel-held areas of Aleppo since December.
Rights groups have decried the regime's use of barrel bombs as unlawful because they lack any guidance mechanism, causing indiscriminate casualties.
Tens of thousands of people have fled rebel-held districts of Aleppo because of the bombings.