The line indicates that the narrator was on his duty and had no way to help him out. The old man had no family and not even any acquaintance nearby. What was more, he was not able to walk farther, as he had already walked twelve kilometers and it was too much for his age.
 
Actually, this signifies that the old man was left in the hands of fate. Displaced, disoriented and alone, he was faced with the inevitability of death. By depicting this wretched condition of the old man, the writer draws our sympathy for the old man and urges the readers to ponder on the tragic effects of war upon countless such innocent people.