This is continuation of the tribal culture.
Honour killing as an ancient practice in which men kill female relatives in the name of family 'honour' for forced or suspected sexual activity outside marriage, even when they have been victims of rape. Reports indicate that offenders are often under 18 and that in their communities they are sometimes treated as heroes.
Family Honour was the most important aspect for siocial acceptability.
A STUPID custom, but illiterate people can hardly understand. It is changing. In the Moslem society, such indiscretions as illicit sex or being raped is taken very seriously since in the villages it is a closed society.