The declaration means police and protective service officers will conduct searches across inner Melbourne including the CBD, Docklands, Southbank, the sporting precinct, and parts of South Melbourne, from Sunday, until May 29, 2026.
The move has sparked community concern, with Inner Melbourne Community Legal warning that the powers will infringe on civil liberties and the freedoms of people visiting the city.
Nadia Morales, the group's chief executive, said the declaration was unprecedented, adding it was a "complete overkill".
"What it means is that a police officer or protective services officer can stop and search anyone, no questions asked, at any time in the CBD and its surrounds," she said.
"For a city that claims to be the world's most liveable, it is a sad day indeed."
The powers will allow officers to search a person or vehicle without a warrant, including asking someone to remove outer clothing or to take bags and items out of their pockets.
Police can also carry out searches using an electronic wand, or pat down.
The increased powers could target minorities and vulnerable or marginalised groups, Ms Morales said.
"People who are stopped randomly by police tell us it is humiliating and makes them feel like they have done something wrong," she said.
"Removing the need for police to suspect a person has committed a crime takes away civil liberties, the right to privacy and to move freely, from all Victorians who enter the CBD these holidays right up to past Easter."
It comes as research from the Centre Against Racial Profiling was published on Monday, that found that Aboriginal, African, Middle Eastern and Pacific Island communities are disproportionately targeted in searches.
Victoria Police has a zero tolerance towards racial profiling, a spokesperson told AAP.
"Our officers are well trained to police in response to a person's behaviour, not their background," the spokesperson said.
"If you aren't carrying a weapon, you don't have anything to worry about."
Police said the operation would be an "invaluable tool in assisting police" with removing weapons from the streets, as knife crime in Victoria has risen.
