It's about 9 o'clock in the morning, and already it's been a long day for Abu Anas. He has lost two men to a sniper serving the Syrian regime. Four more have been injured.
But Abu Anas walks with a striking calm through the bombed-out, ruined streets of Aleppo, a city that has been at war for months. He wears a black headband bearing Islam's holy creed: "There is no God but God.