Around 1,000 explosives have been found underwater by a group of keen magnetic fishermen.
Emergency services, including the bomb squad, were called by the hobbyists who found the stash during an event on Sunday (January 9).
It is believed the devices were long-forgotten railway explosives.
Sophie Doyle who runs the Magnetic Pull Facebook group for the fishermen - who use a strong magnet attached to a rope to discover metal objects underwater - told the Manchester Evening News : “The police and the bomb squad were really shocked when they saw the big pile of explosives that we had piled on the floor for them.
"We weren't able to identify what model they were, there were so many different models of them."
“They had been there for a very long time.”
The haul, found in Daisy Nook Country Park near Oldham, was the second found by the group in a week as they also found more than 200 explosives the weekend before.
A spokesperson for Greater Manchester Police said: "Officers were called to a report of possible unexploded devices found in a canal in Daisy Nook Country Park in Stannybrook Road, Failsworth, just after 5.30pm on Sunday (January 9, 2022).
"Officers and the Explosive Ordnance Disposal Unit (EOD) were in attendance alongside Greater Manchester Fire and Rescue Service.
"A 50-metre cordon was in place as a precaution. All devices were removed and the area open again at 9pm.
"Devices were taken away by the EOD for testing."
Last year a group of magnet fishermen found a body in Rochdale Canal. Police later confirmed a man was found dead in the area.
Magnet fishing has risen in popularity in recent years as people discovered the hobby on YouTube.
