Frustration with illegal immigrants turned to rage last week when an angry mob attacked a Roma gypsy camp outside [of] Naples.

Sometimes, I see 'of' is not used. Is there any difference?


In a context like this, 'of' is not necessary.

To the best of my knowledge, "of" is optional here in both formal and casual usage.

You might try some Googles. (I don't think you'd find "of" in a news report.)

- A.
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Thanks, Clive and Avangi. I've seen both versions in news articles. In fact, this is one of them. Maybe it wasn't written by a native speaker. Thanks!
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