Nigerians are being warned that some bottles of Sprite are contaminated.

"Particles" have been found in five crates of the soft drink at shops and a production facility, says the National Agency for Food and Drug Administration and Control.

It is not clear what those particles are, but the authorities say it is the 50cl-size Sprite bottle in particular that is affected.

Some consumers online say the announcement is too vague and are demanding more information.