Media playback is unsupported on your device Media caption Passenger on board the train to Paddington: "I felt like ripping my hair out"

First Great Western has apologised after hundreds of passengers were stranded in a broken-down train for almost six hours.

The operator said there were just under 500 people on the Penzance to London Paddington service when it stalled near Pewsey, Wiltshire, on Sunday.

It said the delay was "unacceptable" and refunds would be given.

Passengers described the journey as "horrific" and claimed they were "treated like cattle".

The train was at a standstill for five hours and 40 minutes, arriving at Paddington at about 22:15 BST.

It was caused by a fractured air pipe, which caused the brakes to lock.

'Train overcrowded'

A woman on board told the BBC: "They ran out of food pretty quickly. They ran out of food the first or second hour into the breakdown and then water - I think they were giving out water to children and the elderly but that was about it."

Another passenger added: "The train was overcrowded before it even broke down. There was probably 20 or 30 people in each carriage who couldn't sit down."

Media playback is unsupported on your device Media caption First Great Western managing director, Mark Hopwood: We will learn lessons from what happened

The BBC was also told toilets were not functioning before the train broke down and passengers who had been standing after the train stopped were told they would have pay extra to make use of available seats in first class.

Dan Paynes, from First Great Western, said the upgrade demands "absolutely shouldn't have happened. It was completely unacceptable".

First Great Western managing director Mark Hopwood said there was "no doubt it wasn't a good experience in any shape or form last night".

He said: "Clearly what I need to do is say sorry.

"We are sorry. We need to investigate what's gone on and we need to learn some lessons quickly from this.

"It took a lot longer to find the fault than we wanted."

He added that all the affected customers would receive a refund and "appropriate compensation".

'Extensive work'

A spokeswoman for First Great Western added that a "delay of this magnitude is unacceptable and a full investigation will be carried out".

She said: "Our priority was to make sure our customers were looked after on the train and to get them moving as soon as we could.

"After extensive work to the train to get it moving, customers were met at Reading and London Paddington to make sure they could get to where they needed to go."

A number of people on board the train vented their frustration on Twitter.

One passenger, Sarah, tweeted that they had been "treated like cattle", adding: "No food, no water, no air con, no toilets flushing!

"Management on trains not communicating with passengers at all."

Mike Haydock tweeted: "Horrific journey with @FGW - train just started moving again after a five-and-a-half-hour standstill."