Troublemakers have been told to stay away from Melbourne's annual Moomba Festival or prepare to spend the night in police custody.
Commander Tim Hansen told reporters more police resources would be deployed this year than ever before to ensure the four-day celebration remained family-friendly.
"If there are those of you ... that want to come into Moomba and want to cause trouble, and cause harm to those families that come down to celebrate Melbourne, we will be here in force waiting for you, and ready for you," he warned.
"We have cleared out the cells so if we need to, we will arrest you and accommodate you for a night."
The warning comes after brawls and riots at the festival in 2016.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Commander Hansen said the force had been planning for the event during the past month, with no specific threats identified and encouraged families to come.
"For us, and our people, this is a celebration about Melbourne. We really want to be able to celebrate it with the citizens of this great town," he said.
Police will flood the city on horses, bikes, in boats, take to the sky in helicopters and even have the public order response unit out.
But it's not all serious with plenty of food, entertainment, water sports and the famous Birdman Rally at the festival which wraps up on Monday.
Among the fun, there are silent disco tours and the Australian Skateboard League Finals on Saturday before nightly fireworks light up the city sky.
Festival monarchs meteorologist Jane Bunn and sports legend Archie Thompson will be front and centre at this year's parade on Monday.
