Vic rolls out loud terror alert system

Loudspeakers are being installed at more than 90 sites across Melbourne's CBD as part of a terror alert system to be publicly tested after Christmas.

Sixty-five speaker sets have been installed at sites including Federation Square, Flinders Street Station and the Bourke Street mall and the remainder will be completed by the end of 2018.

"Victoria is essentially a very safe place but nonetheless we do need to take these actions so that we can target harden and make sure that we are resistant to terrorism," Acting Assistant Commissioner Shane Patton told reporters on Monday.

The system will be tested on December 28 near the State Library.

"The public won't be put at any risk, that will be made clear to them that it is exactly that, a test," Mr Patton said.

"It will have the standard emergency warning system as comes across in all emergencies, and there will be instructions given but it will be a test of our capabilities to make sure they do work."

Along with the speakers, the state government is also rolling our permanent bollards and increasing CCTV coverage.

Victoria Police will decide when the speakers are used and what message is broadcast.

Police Minister Lisa Neville said the test would go for a "short time" and be an opportunity for the community to experience how the speaker system will work.

"These speakers can be isolated, so we can use them in individual areas or right across the CBD depending on the nature of the emergency," she said.

The system would be a part of the Victoria Police network, with stringent controls to make sure it is not vulnerable from non-authorised use or hacking, she said.

Sydney has had a emergency speakers in place since before the 2007 APEC meeting and other cities around the world use a similar warning system.

Mr Patton told Victorians to feel safe this festive season.

"If there was a risk we would advise the public," he said.

"We don't have any specific risks at this time for any of our major events and we would encourage people to continue to come into the city, come into the CBD, enjoy themselves, go to all the major events."