KABUL — Afghan women are frequent victims of abuse, despite some success by authorities in prosecuting rape cases, forced marriages, and domestic violence under a three-year-old law, according to a report issued Tuesday by the United Nations.

The report came out a day after gunmen shot and killed the head of the women’s affairs department for eastern Laghman Province. Afghan officials said Najia Sediqi, who took the job after her predecessor was killed in a bomb attack in July, was on her way to her office when she was shot dead.