How to delete protected folder?

Question

I'm using external NTFS HDD via Tuxera-NTFS.Suddenly some of my folders turn to be protected (I don't now how it has happen):

I'm trying to delete such folders but still without any luck. I've tried to uncheck 'Protected' checkbox in folder properties pane, I've tried rebooting, I'm always logged as admin but still can't delete those folders.

Any ideas?

UPDATE 'rm -rf' says 'Operation not permitted'