Who was referred to by Lord Mountbatten as the "one man frontier army"?

Lord Mountbatten, the last Viceroy of British India, referred to Mahatma Gandhi (M. K. Gandhi) as the "one man frontier army" because while communal riots were breaking out across the nation during partition, Gandhi single-handedly restored peace and controlled violence in riot-torn areas like Noakhali through his presence, fasting, and dialogue.