Birmingham New Street station was evacuated after a suspected grenade was found on platform 1, triggering a security alert.
Passengers were told to get "as far away from the building as possible" according to some people at the scene amid the security threat.
The bomb incident at the busy train station saw all lines blocked and all services running in and out of the station delayed as a 100 metre cordon was put in place.
One person at the station claimed the conductor on the 15:28 from Derby told passengers a suspected grenade had been found at the station on platform 1.
The station has since been evacuated entirely and on the ground, there are alarms going off as people were warned to get away from the station as police and ambulances descended on the scene of the incident.
It was later confirmed that the grenade was not in fact an explosive, but a 'cannabis grinder'.
One police officer at the scene told The Mirror that they expected the rail hub to be shut for at least two to three hours but could be longer and said it was a "serious incident, firearms related."
CrossCountry trains said: “Due to a security alert at Birmingham New Street all lines are blocked.
“Train services running across the whole CrossCountry network will be delayed. Disruption is expected until 16:15.”
They since extended the expected disruption until the end of the day but have said they expect services to reopen tomorrow morning.
National Rail also warned of disruption at the major UK rail hub as one conductor told passengers that trains were quite literally queuing up to get into the station.
Other videos from the station show hundreds of people being evacuated and flooding into the city centre or waiting around outside as emergency teams responded.
One of the countless commuters travelling described the evacuation as "chaotic scenes" but said staff were doing an "excellent job".
A spokesperson for the British Transport Police said: “Officers received a report of a suspicious item on a platform at Birmingham New Street at 3pm today (31 October).
"The station has been evacuated as a precaution and a cordon is in place while specialist officers attend to assess the item.”
The Mirror understands the suspicious item was a suspected grenade found on platform 1.
West Midlands Ambulance service said: "We are aware of reports of a suspicious item at New Street Station in Birmingham.
"Ambulance crews are working with colleagues from @WMPolice @BTPBhm and @WestMidsFire.
"The station has been evacuated as a precaution while the item is assessed."
One Brit stuck on a train bound for Birmingham New Street before the suspected grenade was found told The Mirror: "I'm just currently stuck on a train that was due to come into the station when it suddenly stopped.
"We were told that its a potential 'package' is on one of the platforms. They are giving out free mini water bottles to those who need it. We are not sure when we will get off."
The security threat has caused widespread travel chaos that is expected to spread well into the evening.
With no trains going in, or out, of the station, thousands of people face a chaotic evening ahead and where possible passengers were asked to delay travel until tomorrow.
For example, one Brit travelling into New Street had already faced the long journey from Cornwall, only to get stopped not far from Birmingham city centre. As things stand alternative transport still hasn't been laid on for them.
Footage filmed from one of the nearby office blocks shows the usually busy train station eerily empty approaching rush hour, surrounded by a ring of police.
British Transport Police told the Mirror that "the item has now been assessed and deemed non-suspicious. It’s a cannabis grinder designed to resemble a hand grenade."
The station is now reopening to passengers.
