Three arrested over Vic Porsche carjacking

A teenage boy and two men have been arrested after the carjacking of a Porsche in Melbourne overnight.

The Porsche was hit from behind by another car on Nicholson Street in North Fitzroy and the driver was threatened with a firearm by a man about 10.40pm on Saturday.

At 4am on Sunday police arrested a 24-year-old Springvale man, a 22-year-old Surrey Hills man and a 16-year-old Keysborough boy.