An Indigenous man carrying a didgeridoo says police swarmed him after a false alarm shut down Melbourne trains during rush-hour on Thursday morning, when a passenger wrongly believed a gunman was onboard.

Riot police shut down Flagstaff Station for about 40 minutes from 8.30am, after a traveller reported a man acting strangely with a gun bag.

Inspector Jacob Bugeja later said it was a sports duffel bag that looked “nothing like” a gun bag, and that the man in question was doing breathing exercises.

Keerray Wurrung and Peek Wurrung man Will Austin took to social media to claim he was swarmed and searched on Thursday morning.

He told The New Daily he was not the person who sparked the initial phone call to police, and that his Facebook post was taken out of context.

“People have got the narrative mixed up. I was stopped by the police due to looking suspicious and carrying something that may have looked like a gun case,” Mr Austin said.

“However I was not the one that caused the initial hold up. People have taken my post out of context.

“I got stopped by the police and searched due to me looking suspicious and I was on the same train. But wasn’t actually the one.”

But he was not doing breathing exercises on the train and was not busking.

He said he was carrying a bag full of artefacts and a Yidaki – an instrument from the Yolngu people of North East Arnhem Land, known generically in English as a didgeridoo.

“I’m not carrying no rifle or ammunition fellas,” he wrote on Facebook earlier on Thursday.

The comment accompanies a photo of Mr Austin holding the Yidaki in a black case.

Mr Austin told The New Daily he was chased and searched by three police officers, about 50 metres from Flagstaff Station, when he was on his way to Treasury Gardens to host cultural workshops for Yarn Bark.

Police looked through his bags, which included a “really large backpack”, and said he “probably looked a little bit funny” with all his belongings.

But he said they were otherwise polite and did a good job.

“The important thing is that everyone’s safe,” Mr Austin said.

Chaos hits morning commute

Premier Daniel Andrews thanked Victoria Police for its swift response.

“Thankfully it was a false alarm,” Mr Andrews wrote on Twitter.

Social media was flooded with images of police swarming the Flagstaff Station and of packed platforms and panicked commuters, when all City Loop services were diverted straight to Flinders Street Station.

City Loop services were suspended until after 9am.

Riot squad at Flagstaff station, apparent gunman in tunnel. Trains running direct to Flinders Street pic.twitter.com/wkq41EXsZG — Liam Vertigan (@LiamVertigan) March 27, 2019

Victoria Police Chief Commissioner Graham Ashton spoke on 3AW radio on Thursday morning, after the incident had been resolved, addressing rumours the train driver made a public announcement that there was a gunman on the run in the tunnel system.

“Oh dear … we’ll pick that up, if that’s the case, and follow it up with Metro,” Mr Ashton said.

“We have to be really careful about the sort of communications that are put out and when they’re put out. You don’t want people to be reacting in a way that might put their safety at risk.

“Fortunately, people are able to get back on their way. We’re sorry for the interruption, but we had to obviously take action quickly and the critical incident response team did respond quickly.”