Syrian opposition activists say military helicopters have dropped barrels packed with explosives in the government's latest air raids on rebel-held areas of the northern city of Aleppo, killing at least 23 people including a family trapped in a burning car.
In Aleppo, the raids with barrel bombs, as the crude weapons are known, have flattened residential buildings, forcing defenders to flee and allowing government troops to advance, the activists say.
Saturday's attacks killed 13 people in the al-Bab area of Aleppo, Hassoun Abu Faisal of the Aleppo Media Centre said via Skype.
The British-based Syrian Observatory for Human Rights corroborated the information.
The blasts badly damaged buildings and caused a fuel tanker to explode, setting nearby vehicles alight, including one carrying a family of eight who were trying to flee the area as they heard the approaching helicopters, Abu Faisal said.
A video showed men dragging a charred victim out of a smashed building.
"You want a political solution? Here is a political solution!" shouted one man as he pointed at two charred bodies on the rubble-strewn ground.
The man was referring to last week's conference in Switzerland between government officials and opposition activists seeking to resolve Syria's war, which began as a peaceful uprising in March 2011 against the rule of President Bashar al-Assad.
The Geneva summit did not produce any tangible results, but is likely to lead to backdoor negotiations.
Other barrel bombings in Aleppo killed three people near a mosque and another seven people in the Ansari quarter, activists said.
Ansari is frequently hit. On Friday, activists uploaded a video of what they said was a child being pulled alive from the rubble after shelling there.
Scenes of civilians and firefighters pulling out dusty, bloodied bodies from under the rubble have become more frequent as the bombing continues.
The footage appeared authentic and reflected Associated Press reporting of the event.
The barrel bombing in Aleppo comes as Syrian government forces try retake the city, which has been divided into government- and opposition-held areas since mid-2012.
Over the past few weeks, government troops have fought their way to two rebel-held neighbourhoods of Karam Tarrad and Karam Qaser, mostly by flattening residential buildings with barrel bombs, activists said.
The al-Qaeda-linked Islamic State in Iraq and the Levant (ISIL) carried out a twin suicide car bombing on Saturday near a rival brigade near Aleppo, killing at least seven people, the Syrian Observatory said.
In the central province of Hama, ISIL killed a rival rebel leader and six other fighters in an ambush, the group said.
Also in Hama, at least 12 government fighters were killed around the town of Morek, the Syrian Observatory said.
It said rebels, including from the al-Qaeda-linked al-Nusra Front, seized Morek overnight, cutting a strategic regime supply line from Hama city to two military bases in neighbouring Idlib province.
Elsewhere, shelling and an attack by unknown assailants on a supply line in Homs caused residents to lose electricity across the province, as well as the eastern province of Deir ez-Zor, according to the Syrian Observatory.
Syrian troops have taken advantage of infighting between a loose alliance of rebel brigades against ISIL, which is widely despised by other rebel groups and activists.
New death toll
Syria's conflict has killed more than 136,000 people, in the latest count by the Syrian Observatory, which tracks the missing and killed through a network of informants on the ground.
Among the dead were 47,998 civilians, including more than 7,300 children.
In-depth coverage of escalating violence across Syria
The war has also forcibly displaced one-third of Syria's pre-war population of 23 million.
Tens of thousands more are blockaded in rebel-held areas.
They include the Yarmouk area on the southern edge of Damascus, where Assad loyalists have steadily intensified a blockade over the past year.
Activists say this has led to the deaths of over 80 people from hunger-related illnesses or from a lack of medical aid.
Over the past two days, aid workers distributed 2,014 food parcels, each meant to feed a family for 10 days. The UN estimates there are at least 18,000 people in Yarmouk.
Aid workers continued on Saturday the distribution, handing over another 480 parcels by the afternoon, Chris Gunness, the UN spokesman, said.
He said it was not enough to cover the needs of Yarmouk's residents.
Shrunken by malnutrition
Footage carried by Lebanese Al-Mayadeen television showed hundreds of men and women, many with faces shrunken by malnutrition, desperately jostling to reach the distribution point.
"These tense scenes attest to the profound levels of need that pertain in a camp that has been besieged for months," Gunness said.
In another development, an amateur video posted to the internet on Saturday apparently shows ISIL fighters decapitating a man believed to have been a pro-government Shia fighter.
The footage shows armed men in black standing outdoors in a circle around a man who is lying on the grass. One of the fighters leans over the victim and appears to cut off his head with a small knife, cheered on by the others.
Once the head is detached, the fighters holds it up and places it on the man's back before it rolls off and settles on the ground about a three feet away from his body.
The remainder of the three-minute video shows the crowd, which includes several children, talking, laughing and taking photographs of the scene.