Disposal units were sent to moorland in Glossop following the discovery of an unexploded bomb.
Derbyshire Police has now put out a warning about the dangers of coming across such objects.
The force said officers were alerted to the large metal shell on Saturday (February 20) by a member of the public.
It was identified by experts as an unexploded mortar shell, which the force described as 'very dangerous and unusual'.
Glossop Police SNT posted a photo of the finding on their Facebook page.
"Information was received from a member of the public who reported finding something very dangerous and unusual to Glossop Police and Glossop Mountain Rescue," the post read.
"This was in fact identified as an unexploded mortar shell - found on moorland above Glossop.
The Army Explosive Ordnance Disposal (EOD) carried out a controlled explosion at the scene today.
The post added: "If you do see anything similar or are unsure don’t hesitate to contact us.
"DO NOT TOUCH!"
