Massive Tunnel Explosion in Aleppo

September 2014 -- This is said to be Aleppo, Syria, just before a massive explosion thought to be a rebel attack on government forces. It's unclear how many people were killed or hurt in the assault. It's one of several amateur videos posted today that purport to show the continuing violence in Syria's three-long civil war. More video claims to show rebels targeting government forces in the central city of Homs.