How to delete multiple bookmarks at once in Pages?

I opened up an older Pages file, about a 60-page document, and it had hundreds of random bookmarks in it — maybe thousands. Sometimes whole paragraphs were bookmarked, sometime just a space or a return, but every single bookmark was titled "Text2". I checked some other older files, and found the same thing in some of them, but not all.

I actually like the bookmarks feature, and want to be able to use it, but all this Text2 clutter gets seriously in the way. Some of my files are several hundred pages long, and seem to have literally thousands of Text2 bookmarks in them.

I went into the Bookmarks tab under the Documents tab, and discovered that I could only delete bookmarks one at a time. I tried multiple selecting with the shift key and the command key, and neither worked. So, does anybody know how to batch delete bookmarks in Pages?