How do i delete categories from the contacts?

How do i delete categories from the contacts?

When I imported mi contacts to my new zohomail account, some unwanted categories were created.  I can move the contacts from those categories to another but i can`t remove the category itself. I select the category, click on the tab remove category and a small window opens saying "select at least one contact", but the category is empty so i can't remove anything. How can I do that?