Government forces and allies launch major offensive on Aleppo.

Turkey has announced that its fighter jets have carried out their first airstrikes as part of the US-led coalition against the so-called Islamic State (IS) group in Syria.

Syrian government troops carried out hundreds of indiscriminate aerial attacks in the past year, most with barrel bombs, in defiance of a United Nations Security Council demand to stop, a US rights group said, calling for a UN arms embargo.

The United Nations will investigate the possible use of chemical weapons in Syria, which would be “a crime against humanity”, Secretary-General Ban Ki-moon has announced