Warplanes have carried out fresh air strikes on Aleppo, hours after Syria’s government announced an offensive to retake rebel-held areas of the city.
At least 27 people have been killed in the strikes, monitors say, although other reports put the death toll higher. One rescue worker described what happened as “annihilation”.
The government has urged people to avoid positions held by rebels.
US-Russian talks to revive a collapsed truce have broken up without progress.
Activists said both Syrian and Russian warplanes were taking part in the offensive, though Russia has not confirmed its involvement.
