"The women were returning from the city towards their destiny Hazara Town when armed men intercepted the bus and one of them barged inside and started shooting indiscriminately." Abdul Razaq Cheema a local police officer in Quetta told media.
Following the Muharram procession, security measures were already tightened in the capital city of Balochistan and the authorities had already imposed section 144 and ban pillion riding.
Balochistan Chief Minister Nawab Sanaullah Khan Zehri condemned the "unfortunate" incident which "cost loss of valuable human lives".
No group has claimed responsibility for the attack.