Government forces and their allies, with Russian backing, have imposed a siege on the rebel-held sector of the city since early July.
Heavy fighting is continuing around the Syrian city of Aleppo and its neighbouring provinces.
Video footage released by the Syrian government appears to show heavy fighting in the 1070 region of Aleppo, including government tanks shelling groups opposed to President Bashar al-Assad.
The rebels have launched a counter-offensive, clashing with government forces on a number of fronts in a renewed attempt to break the siege in the city’s east.
How many have died?
Quoting human rights activists, the AFP news agency says 13 civilians, nine of whom were children, perished in air raids on rebel-held areas of Aleppo on Friday.
The deaths are said to have occurred in the neighbourhoods of Marje and Hamadaniye.
Aleppo – five facts
- Syria’s strategically-important second city
- Divided in 2012 into rebel and government-held areas
- Rebel-held eastern areas under siege from government forces
- Rebel counter-offensive launched on July 31
- 250,000 believed to be trapped in the eastern sectors of the city
The city and province of Aleppo have been among the areas hardest hit by intensifying violence after peace efforts earlier this year failed and a ceasefire crumbled.
Government forces and their allies, with Russian backing, have advanced in recent months and imposed a siege on the rebel-held sector of the city since early July, when the main exit road from opposition areas was closed.
Since 31 July, at least 115 civilians have been killed in attacks in Aleppo. 35 of them were children.
— United Nations (
UN) <a href="https://twitter.com/UN/status/761294931226980352">August 4, 2016</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script> </p> <p> <blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Syria?src=hash">#Syria</a>: we’re extremely concerned for the safety of all children caught up in the escalating violence in <a href="https://twitter.com/hashtag/Aleppo?src=hash">#Aleppo</a> <a href="https://t.co/S5ZKhRS69Q">https://t.co/S5ZKhRS69Q</a></p>— UNICEF (UNICEF) August 5, 2016
— Kenneth Roth (@KenRoth) August 3, 2016
Amateur video footage also published on Friday showed large clouds of smoke rising from the Talbiseh and Al-Rastan areas in the district of Homs.
Homs was one of the Syrian cities where the 2011 uprising against President Bashar al-Assad first turned into an armed insurgency.
It has been bombarded on an almost-daily basis since then.
Efforts to restore parts of Homs began in July as part of a million-dollar project funded by the UN Development Programme (UNDP)
What the politicians say
Russian Foreign Minister Sergei Lavrov has told US Secretary of State John Kerry that the fight against extremist groups in Syria must be stepped up because they are using poison gas on civilians.
The Russian foreign ministry says Lavrov and Kerry discussed the Syria conflict in a telephone call.
The two men spoke a day after Moscow sharply criticised US behaviour in Syria, accusing Washington of backing rebels who use poison gas against civilians and of killing hundreds in air strikes.