"Forse ci sono addirittura di più."

Translation: Maybe there are even more.

[Viaggiatore]

We say both, but here "sono" is plural.

[oktaya]

Don't we rather say "there IS even more" in English?

[Soglio]

It depends on whether you're talking about a countable quantity. There ARE even more eggs, but there IS even more milk.

[JoolsStone]

'...more of them' not accepted

[PattyinRoma]

'ne' = 'of them', which isn't in the Italian sentence (though probably commonly would be found there, just like in English)

[Gaelen23]

"di più" - "some more"?

[silen03]

It is not correct in Italian. You say: "Ce ne sono di più". (The correct translation of this phrase is "Forse ce ne sono addirittura di più")

"Ci sono di più" is absolutely wrong!

At first I didn't understand the meaning of this phrase because of this mistake (and I'm Italian).