Footage has been released showing brazen thieves stealing motorbikes from Melbourne streets in broad daylight.

One clip posted on social media shows a thief hammering away at a lock on a motorbike as people watch on.

He gets on the motorbike but flees when a security guard starts chasing him.

Victoria Police also released footage showing robbers tailgating people into a private carpark before loading a motorbike into a van.

Sergeant Justin Mercovich said the number of motorbikes being stolen from public locations was on the increase in Melbourne.

"While many of the motorbikes are locked when they are stolen, offenders are using tools to remove security locks," he said.

Victoria Police statistics show during 2013-14, there were 132 motorbikes stolen compared with 107 the previous year.

Sergeant Mercovich said motorbike thieves were going to great lengths to avoid being caught.

"The offenders are often dressed in motorcycle clothing to avoid suspicion and are either walking the motorbikes into laneways to start the ignition or are driving away with the motorbikes loaded into another vehicle," he said.

"We are seeing some instances where brazen thieves are tailgating to enter car parks to steal motorbikes being securely parked inside."

Motorcyclists are being urged to vary their parking patterns and use a bike cover.