David Kelly, 43, was also been banned from football games for eight years.

Cardiff Crown Court heard Kelly was with a group of Nottingham Forest fans who wanted to announce their arrival to rival fans at Cardiff City.

Kelly was stopped at Newport station by officers who found he was carrying an 11cm-long firework and a screwdriver.

'Reckless' action

He admitted having an explosive substance and possessing an offensive weapon.

Ron Christie, defending, said Kelly had "never really grown up" and had followed Nottingham Forest since he was a child.

Judge Stephen Hopkins QC said: "The device is one which had the capacity, by virtue of its pyrotechnic nature, to cause burns or even more serious injury.

"It beggars belief that someone coming to a sporting match had the potential to act in such a reckless fashion."