At least one person is dead and several others injured after a petrol tanker rolled on Melbourne’s Calder Freeway, spilling fuel into a nearby creek, police say.

Up to seven cars were involved in the smash on the outbound freeway near the Western Ring Road just after 8:00am, the Metropolitan Fire Brigade said.

Victoria Police Inspector John Kearney said officers were still trying to determine how many people were inside one crushed vehicle.

“At this stage we’re unsure of how many persons are actually involved in the vehicle we haven’t been able to get to yet,” he said.

“We believe there is one person in that vehicle, whether there are any more, we’re yet to determine.”

Witnesses said they saw emergency workers frantically trying to free people trapped in a crushed car.

“It shocked me to see that unfold … I’ve never seen something like that happen,” Airport West resident Trent Theodore said.

Six people were taken to hospital, Ambulance Victoria said.

Most had injuries to their upper bodies and all are in a stable condition.

Mr Kearney said the major collision investigation unit would look into the cause of the crash.

“Early indications are that the truck has had to take some evasive action as a result of the driving of another vehicle,” he said.

“Which vehicle that is, at this point in time, we don’t know.

“We have several witnesses who have been assisting us with our inquiries.”

Tanker spills up to 20,000 litres of fuel

Metropolitan Fire Brigade assistant chief fire officer Darren McQuade said fuel from the truck had leaked into the nearby Steele Creek.

“What we’re doing now is a plan to remove the fuel, the contaminated water in the creek,” he said.

“We believe it’s anywhere between 10,000 to 20,000 litres of unleaded petrol [that] has leaked out of the tanker.”

He said 45 firefighters were on the scene and foam was put on the tanker and spilt fuel to ensure it would not ignite.

Schools in the area had to relocate students within the grounds.

All lanes on the freeway are closed outbound between the Western Ring Road and Tullamarine Freeway.

Police said they expected the freeway would remain closed through the afternoon peak hours.

VicRoads spokesman Steve Bean said motorists should find alternative routes.

“It’s likely to be an extended closure of the freeway today,” he said.

Extracted in full from ABC.