Section numbers inserted in TOC of epub output

I imported a word document into pages so I could convert to an ePub. All was going well, and then I did another test export as ePub. When I looked at the book on my iPad, I noticed that Section Numbers were now being inserted into the automatically generated table of contents as follows:

Section 1

Chapter title

Section 2

Chapter title

This was not happening earlier and I can't figure out what I did that might have triggered it.

What is causing this and how do I get rid of it? Help!

Thanks in advance.