A burst of fighting in the flash-point Syrian city of Aleppo today appeared to shatter a unilateral Russian ceasefire, signalling a resumption of the Government's offensive to seize rebel-held areas there.
Warplanes - either operated by Syrian President Bashar al-Assad's Government or by ally Russia - targeted the opposition neighbourhoods of eastern Aleppo, residents and rebels said. And, they said, pro-government fighters resumed shelling and ground attacks on rebel positions.
"The attacks have started again, and they are so crazy, so intense," said Zakaria Malahifji, a member of the Fastakim rebel unit , which is battling in the northern city.
He added that the "rebels are preparing for a large-scale offence to break the siege of Aleppo."
Pro-government forces have besieged rebel districts for weeks, leaving the more than 200,000 people in those areas in increasingly desperate circumstances.
Moscow announced a "humanitarian pause" and halted air raids last week to allow rebels and civilians to flee Aleppo. Since 2012, Aleppo has been divided between opposition districts in the east and government-controlled neighbourhoods in the west.
Since Sunday, rebel forces have warned residents in the east to avoid front-line areas, apparently in anticipation of more attacks, including those by pro-government militiamen from countries such as Iran, Lebanon and Iraq.
Before the pause, Russian and Syrian government warplanes had been targeting homes, hospitals and infrastructure in the city's east.
Russia recently signalled a major escalation in Syria, apparently dispatching warships, including an aircraft carrier that can hold as many as 40 planes. A spokesman for Russian President Vladimir Putin, Dmitry Peskov, upped the ante by vowing that all of Syria had to be "liberated" by Assad's forces.
Aleppo has become a key battleground in the conflict, which began in 2011 and has killed more than 400,000 people. Seizing the eastern districts of Aleppo - Syria's commercial hub before the war - would mark a major victory for Assad.
The Syrian Observatory for Human Rights, a Britain-based monitoring group, said on Sunday that more than 2100 civilians, including 479 children, have been killed in Aleppo in the past six months.