Manitoba's children's advocate says an alarming number of indigenous girls are killing themselves — a disturbing trend which should be included in the upcoming inquiry into missing and murdered aboriginal women.

Darlene MacDonald says she made the suggestion to Indigenous Affairs Minister Carolyn Bennett in a letter last week.

MacDonald says more than half the suicide deaths she has investigated in the last three years have been indigenous girls.

She says the reasons why some girls kill themselves are the same as factors that lead them to be exploited and vulnerable.

She says the inquiry could explore ways to ensure indigenous girls have some hope for the future and don't see suicide as an alternative.

MacDonald's comments come after several suicides by members of Manitoba's Cross Lake First Nation — the youngest victim was a 14-year-old girl.