Police advised people to avoid the area around the station.
"We are not aware of any serious injury", the statement added.
Trains are now not stopping at Southgate Tube station due to concerns over the suspicious package.
The incident occurred shortly after 7pm at Southgate Tube station in north London.
The station has now been closed as police, ambulance and fire services remain at the scene and parts of the Piccadilly line are now closed.
Twitter user Hal wrote: "I was at Southgate Station when this commotion started".
Police said they had been called to reports of an explosion and people running at Southgate station at 7.03pm local time on Tuesday. I was outside the station about to enter the 125 bus.
City worker Darren Yarlett, 36, told the Evening Standard that he was attempting to drive home in the area, but found the roads had been tapered off.
Police said a small number of people were treated at the scene.
Police later said the security scare was not believed to be terror related.
Police are now investigating the incident.