can't delete "events from my mac" photos

Under the list of albums on my iPhone photos is something called Events with a subtitle "from my mac." I am not able to delete this folder nor any of the photos in this folder. I'm not sure how they got there or in this album configurartion, but sure would like to remove it from my iphone photos, but when I touch "edit" on the albums page, deleting this folder is not an option. Nor are any of the photos in it available for the delete or trash option. How do I get rid of these photos??