Four police officers have died after being hit by a truck on Melbourne’s Eastern Freeway as they dealt with a speeding Porsche driver.

The four officers were killed when the truck ploughed into them as they stood on the freeway near the Chandler Highway at Kew about 5.40pm on Wednesday.

The driver of the Porsche then fled the scene, Victorian Police Commissioner Graham Ashton told reporters.

He said two officers intercepted the Porsche which had been speeding on the freeway and called for backup when they decided to impound the vehicle, with two other members soon arriving.

Shortly after, the refrigerated truck ploughed into the two senior constables and two constables.

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Emergency services at the scene. Credit: DAVID CROSLING / AAPIMAGE

Police are currently in the process of notifying the victims families.

“The Police Association Victoria is shocked and immensely saddened by the deaths of four of our dedicated members, who were killed while protecting the community on the Eastern Freeway this afternoon,” association secretary Wayne Gatt said in a statement.

The truck driver has been taken to hospital with non-life-threatening injuries.

Images from the site show a damaged police highway patrol car and a struck SUV near a large, white semi-trailer.

A black car is crumpled underneath the truck and has been covered in a blue tarp.

Victoria Police Chief Commissioner Graham Ashton (centre) is seen near where Emergency services responded to a collision. Credit: DAVID CROSLING / AAP

“We are providing immediate and ongoing support to the colleagues and families of those members,” The Police Association Victoria said in a statement.

Chevron Right Icon ‘we will never forget them.’

“This is a brutally sad reminder of the danger police face in the course of their service, every minute of every shift.

“We mourn their loss, we grieve with their families and colleagues and we will never forget them.”

Massive delays

The eastern freeway is closed at Bulleen Road with long outbound delays.

Motorists are being urged to exit the citybound lanes as soon as possible and find an alternative route.

Emergency services are currently responding to a collision in Kew where it is understood a police car was hit by a truck. Credit: 7NEWS

The closure at Bulleen Road will send motorists toward Doncaster Road through Balwyn North.

Drivers can return onto the freeway from the Chandler Highway entry.

Victoria Traffic is urging motorists to leave extra time.