Victoria Police detectives are hunting a group of youths accused of 21 offences across Melbourne's bayside and south-eastern suburbs over five days, with police alleging the group used two stolen cars to target mostly lone women.

No one had been arrested by Friday evening. The Southern Metro Region Crime Squad is leading the investigation, and local police have stepped up patrols across the affected suburbs.Police say the offending began at about 5pm on Monday 21 September, when several teenagers allegedly stole a white 2026 Haval Jolion and a black 2017 Honda Odyssey from outside a gym in Glen Waverley. The Honda is now carrying stolen number plates, XUW815, police said.

On Wednesday 23 September, the white Haval allegedly pulled up near a 74-year-old woman on Beach Road in Beaumaris. Police say a youth in a balaclava jumped out of the passenger seat and took hold of her handbag, which had cash and her phone inside. She was left with minor injuries after a brief tussle, and the SUV was driven away down Beach Road.

The next day, police allege the same car stopped near the corner of Bluff Road and Highett Road in Highett, where a young man in a balaclava again got out and took a 54-year-old woman's bag containing her purse. She escaped injury, and the SUV was last seen heading north on Bluff Road.

The most concentrated run of offending came on Thursday night. At about 7.45pm, police allege, several members of the group dragged a 64-year-old woman standing at the lights outside Chadstone and took her shopping. Not long after, another woman near the centre was struck in the face and lost her designer purse.

Go Ad Free

In Clayton at about 8pm, a woman was knocked down on the Princes Highway and robbed of her bag. Ten minutes later, a woman walking out of a hair salon on Bluff Road in Highett lost her handbag. Police say four women were robbed in that window of roughly 25 minutes.

At about 8.40pm, the group allegedly hung around a Black Rock convenience store on Bluff Road, then went after a male worker with a machete and took cash. He was not physically injured.

Police have not given details of every offence attributed to the group, which they say also includes armed robberies, aggravated burglaries, an attempted aggravated burglary, a theft of number plates and eight petrol drive-offs.

Southern Metro Region Detective Acting Inspector Chris Hayes said the scale of the offending would worry residents.

"We know these incidents will be concerning to the community, particularly given the number of offences committed in such a short period," he said.

"Let me be absolutely clear: no one should have to change the way they live, work or move through their community because of the criminal actions of others.

"We are committed to identifying those responsible for these brazen and cowardly acts and bringing them before the courts."

Police have published images of the white Haval and are asking anyone who witnessed the incidents, or has footage or information, to contact Crime Stoppers on 1800 333 000 or at crimestoppersvic.com.au.