Disgruntled commuters were an hour late to work on Thursday morning after electrical sparks shot from the roof of a train carriage in central Melbourne.

Power line connectors exploded over a train carriage shortly after it pulled out from Flinders Street Station on the Sandringham line about 7.20am.

A second train heading towards the city lost power due to damage from the sparks.

More than 300 passengers were stranded on the trains before they were assisted onto the tracks about 8.30am. Many passengers then walked up to Batman Avenue and made their way to work.

The incident caused delays through the day. Trains are not operating between Elsternwick and South Yarra.

Buses were running from Elsternwick to Caulfield since just before 9.30am. Commuters between Ripponlea and Prahan should take local trams or buses.

Repairs are expected to be completed in time for the afternoon peak.

https://twitter.com/benyeo/status/892862024127881216

Metro Trains will investigate the cause of the power fault, and said passengers were not in danger.

“Just before 7.30am this morning, an overhead power issue on the Sandringham line between Flinders Street and Richmond Stations caused the pantograph, which sits on top of the train, to come down and this caused some loud noises and sparks,” a spokesperson said.

“At no point were passengers in danger but we understand that it would have been concerning for our passengers to see sparks. As a safety precaution the Metropolitan Fire Brigade attended and left shortly after as there was no safety risk or fire.”

Passengers complained of being up to an hour late or more.

“Just another fantastic job by the Melbourne Metro service, 40 minutes late,” a Melbourne chef wrote on Instagram.

Another passenger said he missed a business meeting with a CEO because of the delays.

Others questioned whether they would be charged for not tapping-off their Myki public transport card.

“Sorry in advance for not touching off, I was a bit busy climbing out the front of one of your trains.”

Some passengers took to social media to thank the driver for keeping the tense situation under control.

He reportedly made jokes over the PA system: “What do eggs hate the most? Fry-day.”

Passenger Assad Muccadan told the ABC his train was close to Flinders Street when it stopped.

“They just did an announcement [saying] we don’t know what’s going on and they’re going to evacuate all of us out of the train from the middle and it’s just a pain,” he said.

“Since then we’ve been stuck and it’s almost an hour and it’s a terrible situation.

“There’s nothing much we can do.”

Video of the sparks, taken by passerby Ben Yeo, said he saw the sparks as he pulled into the carpark at Federation Square.

“When I was getting the ticket out of the machine I heard this massive spark and crack and saw some smoke coming up,” he told ABC Radio.

“It happened again, so I thought I’d pull out my phone and see what was going on and took a quick video.

“It happened a third time but I had to rush off to work.

“The transformer of the train had a little fire coming off it. I figured that’s what was causing the delays on the Sandringham lines.”

https://twitter.com/whoisdanze/status/892894084909510656

@metrotrains – sorry in advance for not touching off, I was a bit busy climbing out the front of one of your trains with @natbane https://t.co/JsXxO7HIlB

— alexandra post (@apost29) August 2, 2017

-with ABC