Selection Sort Strings

I read a file with cities and its population and I am trying to sort the cities alphabetically using a selection sort. The issue is that for some reason it sorts it in an odd way. The order of the "sorted" list is "ABDCEFHG..." I tried following it but I can't understand where it messes up. This is the code:

    //Selection
    for (int i = 0; i < cities.size() - 1; i++) 
    {
        int minPos = i;
        for (int j = i + 1; j < cities.size(); j++) 
        {
            if (cities.get(j).compareToIgnoreCase(cities.get(minPos)) < -1)
                minPos = j;
        }
        swap(cities, minPos, i);
    }
    System.out.print("\nSelection: ");
    for(int i = 0; i < cities.size(); i++)
        System.out.print(cities.get(i) +"|");

private static void swap(ArrayList <String> a, int i, int j) 
{
    String temp = a.get(i);
    a.set(i, a.get(j));
    a.set(j, temp);
}

Any idea what's wrong?

Thanks