Un Lun Dun

I'm reading Mieville's "Un Lun Dun" because I like the premise and I liked excerpts from it. I haven't read anything by him yeat.

So, whatever the fuck is with those "***" every three or four sentences? Is he using them to seperate paragraphs, and paragraphs to seperate sentences, or somehting? Or is it just shutty editing in my ebook?

For example,

Chapter 2
"Signs"
For the rest of that day Zanna tried to avoid her friends. They eventually caught up with her in the lunch
queue, but when she told them to leave her alone it was in such a nasty voice that they obeyed.
“Forget it,” said Kath. “She’s just rude.”
“She’s mad,” said Becks, and they walked away ostentatiously. Only Deeba stayed.
She didn’t try to talk to Zanna. Instead she watched her thoughtfully.
That afternoon, she waited for Zanna after school. Zanna tried to get by in the rush, but Deeba wouldn’t
let her. She crept up on her, then suddenly linked an arm into one of hers. Zanna tried to look angry, but
it didn’t last very long.
“Oh, Deebs…what’s going on?” she said.

* * *

They made their way to the estate where they both lived, and headed for Deeba’s house. Her boistero ...
etc.. WTF, seriously.