Police have stepped up patrols near Melbourne schools after a teenager was attacked while walking home from class.

A 14-year-old student from Glen Eira College was confronted by a group of offenders who forced him into a car and left him seriously injured in Glen Huntly on Monday afternoon.

There will now be extra patrols in the Glen Eira and Bayside areas, in Melbourne’s inner-south-east, near where the incident happened.

Victoria Police said uniformed officers and those from the mounted branch were focusing on areas around schools.

It is unclear whether the boy was stabbed or ejected from the car during the ordeal.

About 10 minutes before the attack, two men armed with machetes robbed four teenagers of their mobile phones and other personal belongings.

Detectives are still investigating whether the armed robbery is linked. But on Tuesday Detective Acting Senior Sergeant Lisa Watson suggested the men were deliberately targeting students after school.

The investigation is ongoing and anyone with information about what happened has been urged to contact investigators.