Passengers have described the horror on board a high-speed train which derailed on Thursday evening in a tragedy that left two people dead and several others injured.

Authorities say it’s a “miracle” no other lives were lost after the diesel locomotive and five carriages of the Melbourne-bound train careened off the tracks and, according to witnesses, sent people “flying”.

Victoria police confirmed that the two people killed in the crash were the driver, a 54-year-old ACT man, and the train pilot, a 49-year-old Castlemaine woman.

The XPT train, which was carrying 160 passengers, was travelling from Sydney to Melbourne when it derailed at Wallan shortly before 8pm.

A man in his 60s was taken to the Royal Melbourne Hospital in a stable condition with an upper-body injury while 11 others were taken to local hospitals with minor injuries.

At least five police cars and two ambulances arrived at the scene. Photo: Twitter/@Rickard_Scott Photo: Los Angeles Times

One Sydney couple who were on their way to visit their son in Melbourne said they were left hanging on for “grim death” in a “pretty horrifying” train derailment in Melbourne’s north.

Badly shaken up by the incident, the couple decided to cancel their return trip.

“You’re being thrown around, the thing’s going along tilting over and all you can look out the window and just see dirt and debris and stuff flying up past the windows and the track itself is just twisted and bent,” the man told AAP.

“It probably went about 150 metres before it stopped, there were carriages going sideways.”

Police confirmed early Friday morning that the male driver had been killed. Photo: Twitter/@Rickard_Scott

The engine and the first carriage off the train tipped onto their sides near Wallan Station, 45km north of Melbourne, while others were leaning off the wrecked tracks.

About 20 people remain unaccounted for and police have asked people who left the scene without speaking to emergency services, or who bought tickets but didn’t board the train, to get in touch.

Shaken passengers were bussed to Melbourne after the crash, while others were picked up by family.

Passenger Dr Scott Rickard said “fortunately only a few people” were injured in his carriage as “stuff flew everywhere” and “carriages crumpled at edges”.

“Tray tables went flying … We walked out. Most people able to walk out,” Dr Rickard said on Twitter.

“We’re in a bit of shock, but OK. Drinking cuppas now.”

The CFA confirmed five passenger cars were derailed and the locomotive was on its side. Photo: CFA

The train had left Central Station in Sydney at 7.40am and had been due to arrive at Southern Cross Station in Melbourne at 6.30pm.

It was running more than two hours late at the time of the crash.

The track buckled and both carriages shifted at least 10 metres from their normal trajectory.

Passenger James Ashburner from Canberra believes the train was traveling at least 100 km/h when “things went strange”.

“There was a lot of noise and suddenly there was dust, the train was swaying a lot,” he told news.com.au.

“A couple of people had been standing in the aisle and they really went flying … For some minutes we were just milling about seeing who needed assistance and what sort of assistance.”

An “ongoing rail equipment fault” near Wallan had caused the Seymour Line to make delays and cancellations in the past, according to the V Line’s Twitter feed.

It said several of its train services will be replaced by road coaches “until further notice”.

Due to an investigation with NSW Train Link near Wallan, all Seymour, Shepparton & Albury services will be replaced by coaches until further notice.
Customers travelling between Donnybrook & Southern Cross may consider using Metropolitan services. https://t.co/uGDSZHub7u pic.twitter.com/mX0A7cfJD3

— V/Line Seymour Line (@vline_seymour) February 20, 2020

‘Quite a miracle really’

“I imagine as a first responder who turned up it would have been looking like an horrific scene,” Police Acting Inspector Peter Fusinato said.

“I’m very surprised there weren’t more serious injuries … quite a miracle really.”

There are reports one man was injured while trying to save the driver, and Inspector Fusinato said he expected further stories of bravery would emerge.

Investigations have begun and will involve the National Rail Safety Regulator, Australian Transport Safety Bureau and WorkSafe and are expected to take some time.

It could be days before the trains can be removed from the tracks, which also sustained significant damage.

The Australian Rail Track Corporation is in charge of rail maintenance, while the train is managed by Transport for NSW.

-with AAP