A group of children aged between nine and 13 were found playing with a shotgun in a street in Toxteth last night, police have said.
An investigation has been launched the firearm - which had been "recklessly left in a public place" - was found being passed among the children "as if it was a toy", Merseyside Police said.
Detective chief inspector Robbie Slater said: "Thankfully the weapon was not loaded but it could have been and if it had been accidentally discharged an innocent person could have been seriously injured or even killed."
The force's Matrix Serious Organised Crime unit is now investigating how the shotgun came to be left lying around in view of the public.
"Our advice to adults and children alike is to never touch or move the object but instead keep yourself and others a safe distance away and alert the police immediately," Detective Slater added.