Shoppers were said to be screaming and running for their lives after a terrifying incident at the Manchester Arndale shopping centre.
Several customers took to Twitter to say that they had been evacuated and that police were swarming on the building after being called to reports of a man with a gun.
One shopper described "mass panic" as crowds were told to exit the shopping centre, while another said everyone "ran out screaming" amid the chaos.
Several people took to Twitter to express concerns of a "bomb scare" or a "shooter incident".
But it seems that the panic was actually caused by a customer in the centre's food court area.
Police said they were called to the shopping centre at 1.20pm today to reports of a man with a gun, but found no evidence of anyone with a firearm.
Were you caught up in the panic at Manchester Arndale? Email webnews@mirror.co.uk
Andy Appleby wrote on the social media site: "Sat enjoying a subway salad in Manchester Arndale foodcourt, crazy man gets on a table shouting and mad panic ensures.
"Not sure what happened but the rumours are flying."
Another witness described a male standing on a table shouting that he had "something to show everyone" before people began running.
Some Twitter users then said the person in question proceeded to take his clothes off in full view of other diners.
One onlooker told the Manchester Evening News: "The boy, estimated to be 15 or 16, was said to have stood on the table before he started "shushing everyone," "telling them to be quiet" and saying they should "listen to him".
According to the witness, the youth then said: "Can I have everyone's attention please."
He then started to undress, taking a jacket and a bag off, until he was topless. He was wearing trousers.
Arndale staff intervened and began talking to him. Shortly after, the boy ran off, the eyewitness said.
Other shoppers told how security staff were shouting "get out" and telling customers to leave.
A parent who was caught up in the scare wrote on Twitter: "Turned out to be a false alarm but there was mass panic at the Arndale from outside Wilko to High Street, it was chaos people running and screaming. I've never ever felt more instinct to get my kids to safety."
Another witness said he was "herded out by police, at least one with a Taser out. Grabbed my bag and my lunch, and headed away rather than rubbernecking."
Eyewitnesses described people descending the wrong way down the escalators on Market Street, that provide a direct entrance to the food court.
It's believed some of the shops also put their shutters down after hearing and seeing the commotion.
As people were told to vacate the building, they urged members of the public to avoid the area.
"If you're in Manchester, we have just been evacuated from the Arndale because reports of an armed man with a firearm.
"Stay away from the Arndale and stay safe."
One employee who works in the centre said he was told by police to leave the shop.
But he added that he has since been given the all clear to go back into the store.
In a statement, Greater Manchester Police said: "Officers are appealing for information following an incident earlier today at Manchester Arndale.
"Around 1.20pm today, officers were called to the food court at Manchester Arndale in the city centre to reports of a man with a gun. Armed officers attended but found no evidence of anyone with a firearm.
"Witnesses reported seeing a man stood on a table and shouting. He was not seen to be carrying a weapon, but it is believed his actions were intended to cause alarm and panic amongst members of the public.
"The man then fled the scene and enquiries are ongoing to trace him.
"He is described as black, in his mid-late teens, around 5ft 7in, medium build and he was wearing light-coloured tracksuit bottoms. He was not wearing a top, but is believed to have put on a t-shirt as he fled the scene.
Superintendent John-Paul Ruffle, of GMP’s Specialist Operations Branch, said: “We responded immediately to this incident, and thankfully it was quickly established there was no credible threat to the public.
“The man who caused the disturbance was not seen with any weapons, but nevertheless it caused fear and panic to quickly spread amongst people in the Arndale.
“Despite no evidence of a credible threat, we are taking this very seriously. A full investigation has been launched to establish the full circumstances of what happened and enquiries are ongoing to trace the person responsible.
“There will be increased patrols in the area, and anyone with questions or concerns is encouraged to speak to officers on the ground.
“I would urge anyone with information or footage of the incident to contact police on 0161 856 4275.”
Alternatively, information can be passed on to the independent charity Crimestoppers, anonymously, on 0800 555 111.
