Four police officers are dead after a semi-trailer 'speeding at 100km/h collides with two parked cop cars that had pulled over a Porsche' - sparking chaos on a Melbourne highway
Four police officers have been killed after a horror crash sparked chaos and blocked all lanes of a busy Melbourne freeway on Wednesday night.
Dozens of emergency crews remain at the scene of the collision on the Eastern Freeway near Burke Road in the inner-city suburb of Kew.
Footage from the horrific scene shows debris scattered along the freeway, where all lanes are currently blocked.
Police Association Victoria later confirmed four officers were killed in the crash, who are all understood to be from the Traffic Management Unit.
'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,' secretary Wayne Gatt said in a statement.
'We are providing immediate and ongoing support to the colleagues and families of those members.
'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.
A witness told the Herald Sun a semi-trailer ploughed into two police cars and a black Porsche parked in the breakdown lane.
'It was carnage,' the witness said.
'There were civilians trying to run around and help, it was horrible.
Police had earlier pulled over the Porsche driver for a roadside drug test.
It's understood three male police officers from the Traffic Management Unit were unable to be revived at the scene.
Another female police officer is involved while the Porsche male driver is reportedly alive.
'At this stage it is believed multiple vehicles are involved in the collision on the Chandler Highway and a number of police officers are believed to have been involved,' a Victoria Police statement read.
'The exact circumstances surrounding the incident are yet to be determined at this stage.'
Police are expected to provide a further update later on Wednesday night.
An Ambulance Victoria spokeswoman told Daily Mail Australia paramedics were called to the scene just after 5.40pm but were unable to provide any details on patients or injuries.
Witnesses said the truck driver was pulled out of his cabin at the scene by Good Samaritans and is now assisting police with their inquiries.
All lanes of the Eastern Freeway are currently closed between Bulleen Road and the Chandler Highway.
Edit - Update's come through. The Porsche driver did a runner after the crash and is currently missing. Police aren't impressed.