Police believe four or five offenders broke a front window of the Heather Grove home at about 1.45am.

A man who heard the break-in fled to a rear bedroom with his wife, three children and father-in-law, locked the door and huddled there until the thieves drove off in the family's two cars.

The aggravated burglary sparked outrage and despair on social media, with posts complaining about rising crime rates and soft police and government response.

The white Audi four-wheel drive stolen from the house was later found abandoned on Leonard Avenue, Noble Park.

The second car, the family's Toyota Camry, registration UTC 206, was sighted by police in Bourke Street, Melbourne about 3.30am, but the driver evaded capture and the car was last seen heading north down Elizabeth Street.

Investigators from Southern Metro division are examining the case as part of Operation Cosmas​, which was set up in May following a series of aggravated burglaries and carjackings.

The crime spree initially started from the south-eastern suburbs, where criminals were breaking into homes to steal luxury cars.

Assistant Commissioner Steve Fontana, who along with acting Commander Peter De Santo heads Operations Cosmas said the offenders ranged in age from 13 to their mid-20s.

But he said not all were members of the notorious APEX gang.

Last week , police charged two teenage boys - a 17-year-old from Taylors Hill and a 14-year-old from South Yarra with aggravated burglary and theft of a motor vehicle.

The incidents are alleged to have occurred at a property on Shoalhaven Drive, Caroline Springs on Saturday and a property on Wellesley Drive, Taylors Lakes, on Sunday.

In June, home owners used an iron bar to bash two young men who tried to break into their house in Kings Park, in Melbourne's north-west.

Following the spate of aggravated burglaries, police have asked frightened residents not to take the law into their own hands.

Police media spokeswoman Creina​ O'Grady said day and night patrols were being conducted at high-risk locations to prevent offences taking place.

She said there have been almost 80 arrests since the operation started.

That's in addition to the more than 130 arrested by Taskforce Tense, the investigation team that was merged into Cosmas after being set up following this year's Moomba riot.

Anyone with information can submit a confidential crime report at www.crimestoppersvic.com.au.

With Tammy Mills