Western Australia will outlaw gel blasters, going further than any other state in response to concerns about their resemblance to real firearms.
From July 3, the blasters - which fire small gel balls and are nearly identical to firearms - will be classed as prohibited weapons which cannot be owned by anyone.
Anyone subsequently found in possession of a blaster will face a fine of up to $36,000 or three years' jail.
An amnesty period will apply until July 3, allowing owners to hand the blasters into police stations without penalty.
Police Minister Paul Papalia says officers are facing an unreasonable situation when confronted by the blasters, which can be indistinguishable from real guns.
"A tragedy is just waiting to happen with these things," he told reporters on Monday.
"I don't want West Australian police officers to be put into a position where they arrive on a scene, having been called out by a concerned member of the public, and are unable to determine whether they're confronting a real firearm or not."
There were 147 police call-outs to incidents involving gel blasters in WA last year.
Police Commissioner Chris Dawson highlighted a siege at a pharmacy south of Perth in April which led to Tactical Response Group officers being sent in.
"That took hours and hours before that man was disarmed," Mr Dawson said.
"He had a gel blaster - that's what we allege - and that was of grave public concern."
Another incident in December last year involved police responding to a group of six men spotted carrying gel blasters.
"They were apprehended at gunpoint by police," he said.
"We had no concept that they were not real firearms."
Mr Papalia said the blasters were also used as fake weapons to intimidate people and there were concerns they could be converted to cause lethal damage.
The outlawing of the blasters is a regulatory change which does not require legislation to be amended.
Victoria does not allow replica firearms, while gel blaster owners must have a firearms licence in NSW, South Australia and Tasmania.
Queensland allows people to have gel blasters without a licence but they cannot be openly carried.