Any court acting pursuant to the Nebraska Juvenile Code shall commit to the care of the Department of Health and Human Services or any regularly organized and incorporated society or institution, for the purpose of caring for and placing in good family homes, all children, except those already committed to the care of responsible persons or institutions, who have been decreed to be children as described in subdivision (3)(a) of section 43-247 and who for that reason must be removed from the care of their parents or legal guardians.