Newcastle launched a review into their safety operations after the home Champions League tie against Borussia Dortmund was subject of a major security alert.
Eddie Howe's side lost the European clash courtesy of a Felix Nmecha goal - but we can now reveal the game was played amid significant security concerns.
The incident centred around five teenagers who were behaving suspiciously at St James' Park.
The group are believed to have intruded into a restricted area inside the stadium.
It is understood security officials were alerted to the individuals and arrived quickly onto the scene.