Members of Myanmar's Kachin ethnic group have called for justice for two young volunteer teachers who were raped and murdered in a case they believe highlights sexual violence by government soldiers.

A report on the assault was released Tuesday as a memorial service was held in Yangon for Tangbau Hkawn Nan Tsin and Maran Lu Ra, who were attacked a year ago on Jan. 19, 2015, in a remote village in Shan state in northern Myanmar.

Local villagers believe the perpetrators were soldiers who were temporarily based there, an allegation the army has denied. No one has been charged with the crime, which the report says was not properly investigated.

Human rights organizations consider widespread reports of abuses by government soldiers credible.