Hundreds of police will be patrolling the border of Greater Melbourne and the Mitchell Shire to ensure anyone leaving has a valid reason for doing so.
About 1200 officers are on the streets with checkpoints now in place in areas including Longwarry, Avalon and Donnybrook.
One of the checkpoints has been set up in Cheltenham in the city’s south-east.
Police are randomly pulling over cars and asking people who they are and why they are out.
“We will be pulling up cars actively, randomly selecting vehicles and checking what their business is,” an officer told Today.
“We’ll be checking their identity, where they come from, what their business is.”