Women's rights groups are demanding an international investigation into the killing of a Libyan activist who had become a symbol of her country's efforts to create a democracy.

The shooting and stabbing of Salwa Bugaighis shortly after she cast her vote in Libya's parliamentary elections last year shocked the international community, with U.S. National Security Adviser Susan Rice calling the assassination "brutal and senseless."

The women's groups say Libya's authorities have never investigated the murder of the lawyer and mother of two. They are calling on the U.N. secretary-general and the international community to hold accountable those responsible for violence against women in the Arab region.

There has been concern since Bugaighis' murder last June that an investigation isn't possible amid Libya's political chaos.