Comment by ants_everywhere

This seems like it has to vary significantly depending on a number of factors.

Unexploded ordnance refers to ordnance that was deployed but failed to explode. E.g. the bomb was dropped from a plane and just didn't explode.

Deployed mines that haven't exploded are just waiting for someone to interact with them. This seems like it must be the highest risk.

This article appears to be about a cache of unused bombs. They would not ordinarily explode on their own, but if everything is decaying then the safety mechanisms are also decaying so there must be some risk.