I might be wrong and the Daily Trust is quoting the police.

I just don't know. It is perfectly possible that teens could be fooling around, I just don't know. Never heard of fireworks around any embassy before in Nigeria and the US embassy isn't exactly in a heavily populated area. It is a fortress like building in a semi-isolated part of Abuja (near the Chinese embassy which is also quite impressive - somebody is trying to make a statement here).