A tribal jirga (jury) may not have any legal sanction,...

A tribal jirga (jury) may not have any legal sanction, but it continues to operate in many parts of Pakistan, where tribal and feudal systems are still dominant.
In most cases, such a jirga is used by the tribal chiefs to maintain their grip on power. In remote rural areas, people go to a jirga instead of going to the police for resolution of inter-tribal disputes and matters related to "honour".
Under tribal codes, women are seen as men's property and an allegation of "unfaithfulness" is punished by death. Thousands of women fall victim of this oppressive system in Pakistan every year.
A woman suspected of having extramarital relations is declared a kari (sinful) and tribal honour requires a family member to kill her.
Until recently, honour killings under the law would not receive capital punishment. The law was changed after a prolonged protest by women's and human rights groups. But that has not helped to alter the situation. According to one report, more than 300 women are killed every year in Pakistan in the name of "honour." An inter-tribal dispute is often resolved under the jirga system by giving a woman to marriage to the rival group.
Punishing an innocent women for a crime committed by male member of the family is quite common in some parts of the country. Even in urban areas, migrants from tribal regions often form jirga to settle disputes.
This extra-legal system has been strengthened because of ineffectiveness of the official legal system and the falling faith of the population in the police. In most cases people grudgingly accept the jirga verdict because they do not expect any remedy from the State. The fear of being ostracised by the tribe forces people to comply.