A Point Cook teenager is among three people under police guard following a carjacking and crash on Wednesday.
Four teenagers were arrested following the carjacking in Airport West and a crash in Keilor East.
It is believed the group approached a man along Louis Street in Airport West, threatened him with an axe and demanded his black Mercedes about 8.30am.
During the attack, the 25-year-old Forest Hill man sustained minor injuries and was treated at scene.
The offenders fled in the stolen Mercedes and a blue Holden Commodore, seen driving at excessive speeds of up to 160km/h on the Western Ring Road before crashing into a church on Ely Court, Keilor East about 8.40am.
Three of the teenagers dumped the Commodore and fled in the stolen Mercedes on Milleara Road.
The driver of the Mercedes then collided with a police vehicle along Woorite Place and the group were arrested at the scene.
An 18-year-old Reservoir woman, a 16-year-old Point Cook girl and a 14-year-old Ivanhoe boy were taken to hospital with non-life-threatening injuries under police guard.
A 17-year-old Coburg boy is currently assisting police with their enquiries.
It is alleged the offenders were also involved in two attempted robberies across Brimbank earlier this morning.
Anyone with information can contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au