Human rights catastrophe took place in Abyan region of Yemen during the conflict between the government and Al-Qaeda-linked militants in 2011 and 2012, Amnesty International has said.
The rights group says it has evidence of abuses including summary executions and amputations carried out by the Ansar al-Sharia militants.
In its report, 'Conflict in Yemen: Abyan's Darkest Hour', Amnesty said that the militants imposed a strict version of sharia - Islamic law - through religious courts, restricting behaviour, clothing and separating the sexes, the BBC reports.
These courts "frequently imposed cruel, inhuman and degrading punishments on alleged criminals, suspected spies, those accused of 'sorcery', and people who transgressed cultural norms," it said.
The organization said that the punishments included killings without trial, amputations, torture and floggings - the body of one executed man was crucified for several days.
According to the report, the group also accuses the Yemeni government of using "inappropriate battlefield weapons" during its efforts to oust the militants from the region.
Amnesty has called for those responsible to be held to account, the report added. (ANI)