An attempted carjacker remains on the run in Melbourne following two violent attacks on drivers in just 14 hours.

The man beat both victims with a hammer, the second a 24-year-old woman who was left bleeding with head injuries.

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The woman’s husband rushed to help as the would-be thief entered the car on Cardigan Street in Melbourne’s inner north.

“He was beating up whoever was attacking her,” a witness told 7NEWS.

A woman was left bleeding with head injuries. Credit: 7NEWS

A neighbour joined in to help pull the man out of the passenger door.

The attacker was held down on the footpath but broke free and escaped.

The woman was taken to hospital and was later released.

String of attacks

Police had been investigating a series of similar failed carjackings and robberies in recent days.

The man is also believed to have targeted two McDonald’s stores, one in Abbotsford last Thursday and another in Richmond on Tuesday afternoon.

The man also targeted McDonald’s stores in Abbotsford and Richmond. Credit: 7NEWS

Later on Tuesday, he used a hammer as he tried to carjack a Jaguar near Little Lonsdale Street in the CBD.

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Police say he’s perceived to be of African appearance, tall, slim, with short dark hair.

He was last seen running along Palmerston Street after biting a neighbour’s arm who tried to stop him.