Police have charged four Ballarat teenagers in relation to two alleged armed car jackings last week.
Detectives from Stonnington Crime Investigation Unit were investigating a carjacking in South Yarra on 19 September where it is alleged a vehicle was stolen on Williams Street at knife point.
The second incident took place on 20 September on Riversdale Road in Hawthorn.
It is alleged a knife was produced and the offenders attempted to steal a vehicle but were unable to start the car so fled on foot.
Manningham Crime Investigation Unit detectives arrested and charged two 13-year-old girls, and a 15-year-old girl. A 17-year-old boy was also charged by Ballarat Crime Investigation Unit detectives in relation to both incidents.
All have been charged with numerous offences including armed robbery, aggravated car jacking, theft of a motor vehicle, theft, assault with a weapon.
Two 13-year-old girls and a 15-year-old girl have been bailed by the court to appear in a children's court at a later date.
The 17-year-old boy has been remanded in custody to appear in a children's court at a later date.
Police are not looking for anyone else in relation to the incidents.
