Victorian police have arrested dozens of young suspects in crimes such as carjackings and aggravated burglaries as they admit street gangs have "absolutely" become a problem in Melbourne.

Key points: Police said many of the young people involved in "high-harm" crime in Melbourne knew one another

Police said many of the young people involved in "high-harm" crime in Melbourne knew one another Some of those arrested have been charged with what police call "horrendous crimes"

Some of those arrested have been charged with what police call "horrendous crimes" It follows another operation targeting "swarming", in which groups enter stores and steal property

Police made the arrests over three days in suburbs including Cranbourne, Dandenong, Reservoir, Sunshine and Truganina, as well as the Geelong suburb of Norlane.

Victoria Police Commander Tim Hansen said those arrested were aged between 15 and 21, and were allegedly behind a range of "high-harm, high-impact" crimes including home invasions, carjackings and aggravated burglaries.

"What we do know is there are kids out there who seek the notoriety of being in a gang," Commander Hansen said.

"If what we're looking for is an absolute agreement that we have street gangs in Victoria … then, yes, absolutely that's the case."

Commander Hansen said young offenders entering the criminal justice system for the first time were being charged with more violent crime than police had observed previously.

"These crimes include carjackings, aggravated burglaries, armed robbery and serious street robberies — all horrendous crimes which leave a long-lasting impact on victims.

A 19-year-old Cheltenham man was arrested and released pending further enquiries. ( Supplied: Victoria Police )

"A number of offenders would hit retail outlets simultaneously and, by force or coercion, steal mainly electronic items, but also clothing and alcohol."

Suburbs where arrests occurred include: Cranbourne

Cranbourne Clyde North

Clyde North Dandenong

Dandenong Narre Warren

Narre Warren Frankston

Frankston Pakenham

Pakenham Reservoir

Reservoir Sunshine

Sunshine Truganina

Truganina Lara

Lara Norlane

Commander Hansen said arresting the group en masse showed police were "listening to the community" and sent a "clear statement that this offending absolutely has our attention".

"If you keep offending, we are coming after you."

The arrests were part of Operation Liege, which was focused on reducing youth offending across the state.

Commander Hansen said it followed a separate recent police operation which saw 34 people charged over "swarming" offences, where a group of people enter and steal from a store en masse.

Victorian crime statistics released last month revealed the number of home invasions and carjackings had risen over the past year.

At the time, police said combatting those high-impact crimes was an "absolute priority", and they had set up new teams in Melbourne's outer suburbs to tackle the offending.