The incident took place last evening and the victims were identified as Saad Teerandaj and his friend Bilal Ansari, both residents of Mira Road.
"The youths were heading to their college on a scooter when a speeding vehicle hit them from behind on the north-bound stretch of the Western Express Highway near Thakur village in Kandivali east at 5.30 pm yesterday," the officer said.
The impact of the collision was such that the duo fell on the other side of road, he said.
Saad's mother is a principal of a school in Kandivali.
A case has been registered against the unidentified driver of the vehicle and further probe into the case is on.