Bubbling bottom not to blame

A strange odour that lingered around the Nidelven river in Norway was, according to local media, thick enough to cause nose and throat irritation.

Gases trapped by a layer of limestone was thought by some to be the source of the smell  which appeared to be issuing from the Nidelven river in Trondheim

A strange odour that lingered around the Nidelven river in Norway was, according to local media, thick enough to cause nose and throat irritation.