Derailment shock: 'It was just like a monster'

Sydney passengers have told of the terrifying moment a train derailed near Edgecliff this afternoon.

Hundreds were evacuated from the train as the impact drove a metal bar through the floor of one of the carriages.

"There was this girl right in front of me and she was so lucky she didn't get hit," one passenger said.

Some people were hit by metal shards after the iron bar speared floor of the train near Edgecliff, around 5.15pm.

The carriage on the Bondi-bound train is believed to have come off the rails, with an estimated 700 people on board.

No injuries have been reported yet.

Firefighters, police rescue and ambulance officers were called in to ensure passengers are removed safely from the train, which stopped near Edgecliff Station.

"We understand that there's no serious injuries at this time. People are being ferried up to the platform and then they'll be walked up the stairs by police," fire officer Chris Morgan told the ABC on Wednesday.

Off the rails: Sydney train derails near Edgecliff in the eastern suburbs. Photo: Supplied

Police say they are investigating whether the derailment was caused by a brake problem.

Shockingly, the large piece of metal tore through the floor of the train narrowly avoiding frightened passengers.

"It just went through and missed one of the ladies that were standing next to it," Peter Pulu told Fairfax.

"It was just like a monster coming up from the floor. It was not that fast. It went up and hit the roof."

The shocking image of a piece of metal that has pierced through the floor of a Sydney train. Photo: Supplied/KimJong-Unbelievable

The T4 Eastern Suburbs and Illawarra Line is partially closed between Martin Place and Bondi Junction.

The Transport Management Centre said replacement buses will be organised.

Trains continue to operate between Martin Place and the Illawarra.

But some passengers were furious, and expressed their frustration via social media - tweeting the hashtag #cityfail.

Peak-hour pain: Sydney commuters vent their anger over the run-on effects of today's derailment. Photo: Twitter