Two teenage girls were repeatedly punched in the head and one was robbed after being set upon by four other teenagers at Melbourne's South Wharf shopping centre.

Footage has emerged of the shocking attack in which the two teenagers were pushed and punched while shopping at the Direct Factory Outlet on Saturday, January 27.

Both victims were repeatedly punched in the head by their four attackers.

The footage shows one victim being shoved and then struck in the head three times by one of the attackers who approached from behind.