POLICE officers cordoned off Centre Park this afternoon after a suspected hand grenade was found.
Reports suggest officers arrived at the scene around 3.30pm this afternoon, Sunday.
Police cars and vans also cordoned off access along Slutchers Lane.
It is thought the Waterside Pub was also evacuated.
A police spokesman said: "Officers have attended Centre Park after the discovery of a hand grenade, it was pulled from the River Mersey by a fisherman.
"Bomb disposal have now attended and removed the hand grenade, it will be destroyed by controlled explosion on nearby waste land."
Karl McDonald and Martyn Jones found the hand grenade while they were fishing.
Fisherman Karl McDonald, who found the hand grenade, said: "Myself and Martyn Jones were magnet fishing in the river Mersey looking for old coin, relics etc.
"When I found this I had to carry it to my car where our mobiles phones were to call the police and report it.
"As soon as the Warrington inspector turned up he didn't hesitate to call the bomb squad.
"When they turned up they said it was a World War hand grenade which was live and a suspected Mills bomb.
"They then said they would take it to detonate in a field and we went with them to watch."
Click play below to watch the video of the detonation.