Syria conflict: New air strikes on Aleppo

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, The Syrian Observatory for Human Rights monitoring group say. One rescue worker described what was happened as "annihilation".
The government has urged people to avoid positions held by rebels. HoweverUS-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.
Russia supports the Syrian government, while the US backs the opposition. The two powers accuse each other of failing to rein in their respective allies on the ground.