UNITED NATIONS - UN chief Ban Ki-moon on Monday welcomed Somalia's release from jail of a woman who told a journalist she was raped by security forces, but expressed regret the journalist would remain behind bars.

A Somali appeals court dropped charges on Sunday against the woman, who had been sentenced to a year in jail for "offending state institutions," but reporter Abdiaziz Abdinuur's sentence was merely cut in half, to six months.

In a statement, Secretary General Ban urged "the Government of Somalia to ensure that allegations of sexual violence are investigated and perpetrators are brought to justice."

Abdinuur, 25, was detained on January 10 while researching sexual violence in Somalia, but did not air or print any report after interviewing the woman.

He was also found guilty of making a false interview, and entering the house of a woman whose husband was not present.