"On Thursday, 25 August, 11 children and four women were killed in a barrel bomb attack on the Bab al-Nayrab neighbourhood in the south of Aleppo city,” the Syrian Observatory for Human Rights Monitor reported.
The Observatory also said rebels fired mortar rounds into regime-held areas in western Aleppo; eight people were killed, including two children.
Rescue workers and residents dig through the rubble, looking for loved ones through the ruins of collapsed buildings, an AFP journalist in Bab al-Nayrab reported.
One man carried out a lifeless small baby, eyes closed, white dust covered its body except for spots and smears of blood.
Men and women carry dead children covered with dust, sobbing and crying; a Syrian woman screamed in anguish, “I lost five children...!”
A heartbreaking video was posted on ITV News Facebook yesterday, shows two young brothers hugging and crying after finding out that their brother was killed in the bomb blast.
The footage was released by the Aleppo Media Centre, an anti-government activist group.
Last week a video, also posted by the Aleppo Media Center, captivated the world and was a horrifying reminder of the victims of the war in Syria.
The video showed a boy no older than five year old, Omran Daqneesh, dust covered and blood smeared, sitting silently in an ambulance awaiting help. No information about the fate and whereabout of his family.
Aleppo city once was Syria's economic powerhouse, but it has been wrecked by the conflict that began with anti-government protests in March 2011.
The city has been divided between government control in the west and rebel control in the east since mid-2012, each side bombarding the other and causing civilian casualties.
According to the Observatory, more than 290,000 people have been killed in Syria since the conflict began.
In addition to using barrel bombs, which President Bashar al-Assad and his government deny, the Syrian regime has been accused of using other forms of weapons.
CNN reported, the White House condemned the Syrian government after announcing a year-long UN-backed investigation which found President Bashar al-Assad's government and ISIS had used chemical weapons.
US National Security Council (NSC) spokesman Ned Price said Wednesday, "It is now impossible to deny that the Syrian regime has repeatedly used industrial chlorine as a weapon against its own people."
The NSC pointed that the regime has violated the Chemical Weapons Convention and a UN resolution.
In August 2012, Obama described the use of the kind of weapons as constituting a "red line" and if it is crossed would force the US to consider intervening, CNN reported.