AIR strikes on rebel-held parts of the besieged city of Aleppo killed at least eight people on Tuesday.
Meanwhile, shelling of a government-held neighbourhood in a southern Syrian city hit a school, killing at least six people, including children, according to activists and state media.
The northern city of Aleppo, Syria's largest and its former commercial centre, has witnessed fierce fighting in recent months with government forces and their allies trying to capture neighbourhoods in besieged opposition-held parts of the city.
The activist-operated Aleppo Today TV station and Qasioun news agency said bunker-busting bombs were used in an attack on the Bustan al-Qasr neighbourhood in rebel-held eastern Aleppo.
Other activist groups and a member of the Aleppo local council, Zakaria Amino, said the death toll is likely to rise above eight, with rescue workers still searching for people under the rubble. He said bombs fell in a number of other rebel-held neighbourhoods.
The opposition-held part of Aleppo has been battered by an intensive aerial campaign since last month, when a ceasefire collapsed after just a week. Syrian pro-government forces are also conducting a ground offensive into the rebel-held districts, advancing slowly in the north, east and south of the city.
In the southern city of Daraa, where the country's conflict began following anti-government protests in March 2011, rebels fired rockets at government-held areas. One hit a primary school, killing six people - among them five children - and wounding 18 students, according to state-run news agency SANA. It said some of the wounded are in a serious condition.
SANA posted a photo of a boy carried on a stretcher. His grey trousers were stained with blood and his bandaged right hand on his stomach. Another photo showed a boy and a girl inside what appeared to be a hospital with IV drips in their arms.
