Police have arrested six teens after a series of robberies in the western suburbs on Friday evening.
Officers were first called to Pier Lane, Maribyrnong about 5.15pm after reports that a pregnant woman had been assaulted.
Investigators have been told an offender met the woman after offering to purchase a laptop advertised on a trading website.
The 30-year-old woman suffered minor injuries and the offender made off with the laptop before leaving in an allegedly stolen Mazda CX5.
Around 7.40pm another victim was approached in Paisley Street, Footscray by a group of males.
They demanded he hand over his belongings but he managed to run from the group.
Investigators believe the offenders got into a Mazda CX5 and chased down the victim.
They then stole cash and a mobile phone before driving off.
Police were then called to Essex Street, West Footscray about 8.20pm after two 18-year-old men were confronted by two offenders from the allegedly stolen Mazda.
One of the men was chased and forced to hand over his mobile phone.
The offenders drove off but the vehicle was spotted in Sunshine a short time later.
A number of units were called into the area and the car was driven to Stradbroke Drive before being dumped.
The six occupants fled the scene but were all arrested in nearby streets.
Police are currently interviewing a 15-year-old boy from Derrimut, a 16-year-old boy from Sunbury, a 15-year-old boy and a 17-year-old boy from St Albans, a 14-year-old boy from Albion and a 16-year-old boy from Cobblebank.