Syrian rebel fighters began preparations to seize Aleppo a year ago but the assault was delayed by war in Gaza and ultimately launched last week when a ceasefire took hold in Lebanon, the head of Syria's main opposition abroad told Reuters.

The Syrian civil war, seemingly frozen in an uneasy deadlock for years, has been reignited with rebel forces wresting Aleppo, the country’s second biggest city, from President Bashar al-Assad ’s grasp.

Syrian and Russian jets are stepping up strikes on opposition forces in northern Syria in retaliation for the sudden offensive that has cost the regime control of the country’s second largest city, Aleppo.