A discarded grenade found buried in a Preston field sparked fears that another unexploded bomb had been uncovered in the city.
Police were called to a field by Avenham Park after the discovery on Saturday, and initially warned residents to stay well clear.
A metal detector has found an old discarded grenade. It is safe
However, investigations quickly showed the item to be a harmless “rusty” grenade.
It came exactly a week after the park had to be closed while experts carried out a controlled explosion of a potentially live mortar bomb that was discovered in similar circumstances.
Posting on Twitter at 6.20pm, police said they initially believed the latest item was also a mortar bomb and advised people to stay clear of the area around the Old Tram Bridge.
In a tweet, police said: “Another mortar bomb has been found in the field by the Old Tram Bridge. Please stay clear of the area whilst we deal with it.”
But within an hour, officers had confirmed the object was in fact an old grenade and had never posed a threat to the public.
Insp Grant Smith said: “A metal detector has found an old discarded grenade. It is safe.
“It is not a bomb but an old, rusty grenade that is inert.”
The item was cleared by police and the park was fully open again by 8pm.
The weekend before, the park was closed after two metal detectors uncovered a “potentially live and very dangerous” mortar bomb.
Army experts were called in to help dispose of the Second World War relic, found in a similar spot to the grenade.
On that occasion, a couple using a metal detector made the startling discovery and swiftly reported it to police.
Army bomb disposal experts successfully detonated the 3in HE (High Explosive) Second World War mortar the same evening.
At the time, Sgt Paul McLarnon, of Lancashire Police, said: “It appeared the bomb had been there for some time, and there was some corrosion on it.
“Because of its condition, because it was quite old and corroded, it was safer to undertake a controlled explosion in situ, rather than attempt to move it.
“It was in a field and wasn’t close to any roads or houses, so it was safe to detonate.
“Two people got a signal from the metal from the ground whilst they were using a metal detector.
“They exposed the item and did the right thing by calling us immediately.”
Three-inch mortar bombs were used by the British army in the 1930s.
The explosives were usually buried underground.
The three inches refers to the diameter of the devices, which weighed around 4.5kg and had an impact radius of 100 yards.