Amin Abdur Rehman was quite anti of other ethnicity in Afghanistan. The fate those Hazaras suffered during his period people of Kafiristan which is now called Nuristan also suffered the same. The point was after losing some territory to British his power came under the potential threat from Non Pashtuns because he lose large Pashtun Population of his regime to British. The Great Game further made the situation complicated where Russian Empire was in a position to use non Pashtun Elements for Leverage because they had significant number of their Brethren within there territory. due to which he end up Cooperating with British Empire to keep his power in Afghanistan. It was unfortunate situation in which Non Pashtun as well as Pashtun had to suffer during that period.Hazaras took refuge in British domain, after their failed rebellion against Amir Abdul Rehman.......and that rebellion was not for sectarian reasons but they supported his rebel brother for throne.
Hazaras of Quetta are more close to Pashtuns of Afghanistan than with any other community of Quetta.