A government air strike killed 10 people in a rebel-held neighbourhood of Syria's main northern city Aleppo on Tuesday, a monitoring group said.
The Syrian Observatory for Human Rights also reported that some fighters of the jihadist Islamic State of Iraq and the Levant (ISIL) had refused orders to withdraw from a battle with government troops to fight against rival rebels.
"An air strike hit the area of a bus station... in Jisr al-Hajj," in Aleppo, the Observatory said, with its director Rami Abdel Rahman telling AFP: "We have documented 10 deaths".
The Observatory distributed amateur video footage showing a huge fire in the area, located in the westernmost part of Aleppo city.
Warplanes also targeted the Ansari neighbourhood farther east, the Observatory said.
Once Syria's commercial capital, Aleppo has been wracked by violence since a massive rebel assault in July 2012.
Then on December 15 last year, the air force unleashed a brutal air offensive that has killed hundreds of people, mostly civilians, according to the Observatory.
Aleppo-based citizen journalist Mohammed al-Khatieb told AFP via Skype: "Today's attack is part of that assault.
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"There has been aerial bombing every day since December 15, except for the days when visibility was poor because of the weather."
Another video distributed by the Observatory showed a man, reportedly in Ansari district, running with a wounded child in his arms from a damaged building to a pick-up truck.
The child has a visible head wound, with blood on his face that is also covered in dust from the rubble.
Elsewhere in Aleppo province, the Observatory said a group of jihadist fighters had refused to leave a battle front with the regime after being ordered to fight rival rebels.
ISIL has been locked in fierce clashes with Islamist and rebel fighters in much of northern Syria for weeks.
The Observatory said a group of ISIL fighters battling the army and allied militia in the village of Blaat refused to redeploy to Manbij, where rebel-jihadist clashes are underway.
There were no immediate details of the number of ISIL fighters who refused the orders.
More than 130,000 people have been killed in Syria's nearly three-year war, the Observatory estimates. Millions more have fled their homes.