Bomb disposal experts were called to the Peak District after unexploded military shells were discovered.
Members of the Woodhead Mountain Rescue team were alerted by South Yorkshire Police after a fell runner, who was exercising on the moors above Langsett, reported finding a suspect shell.
The mountain rescue team found two more 75mm pre-World War Two shells and the bomb squad was called out to dispose of them safely last Friday.
Duncan Scissons, from the Woodhead team, said: “We were fortunate the runner provided an excellent description of where the shell was and we found it right away.
“However, experience tells us these things never pop up alone and we took the decision to scan the immediate vicinity for further devices.
“It turns out this was the right thing to do, as we found another two shells.
“The shells were exceptionally volatile and, had someone picked them up, they could have exploded at any time.
“Given the size of the shells, they could have caused serious injury, not only to the person who picked them up, but to anyone close by.”
The moors above Langsett were used as firing range between the two World Wars.