Xperia Pro/Neo/V/L :: How To Delete Automatically Synchronized Facebook Photos

My phone is a Sony Ericsson Xperia Neo V, and today I noticed that I had many photos in my gallery, that were not me who put that thing there. So, I find out that my Xperia Facebook has synchronized all the photos like my profile pictures, wall photos, cover photos and all the new photos that friends put on facebook. So, I went to settings and disable the automatic synchronization, and then went to Apps -> Manage apps -> and found facebook, then I clicked on Erase data (I don't know if is this the name of the menu in english, because I'm using in portuguese) and it prompts me telling that this action were going to erase all the files that were with facebook in my Xperia. But even after that, the photos remain in my SD card, it didn't erase. I really want to delete it, but it's impossible trying to select all the albums because it don't have the Delete option.