QUETTA: Three-day mourning is being observed in Balochistan over Quetta tragedy that left at least 72 dead and over 100 injured. National flag is flying at half mast on all public and private buildings. The lawyers community has announced to boycott proceedings of all courts in the province and black flags have been hoisted on buildings of Balochistan High Court and lower Courts. All Bazaars and business centers, educational institutions are closed while traffic is off the roads.