Football chiefs in Scotland will hold an emergency meet on Thursday to investigate how a spectator was able to attack Celtic manager Neil Lennon during a Scottish Premier League match. Celtic\'s opponents Hearts have opened a full inquiry into the incident, which happened at their Tynecastle ground. Celtic assistant boss Johan Mjallby said no one could blame Lennon if he walked away from Celtic after the man\'s shock assault. Gary Hooper had just put Celtic two goals in front when a fan jumped out of the Hearts section of the main stand and lunged for Lennon standing on the touchline. Stewards and Hoops coach Alan Thompson intervened and the assailant was eventually taken away by police in a match Celtic, second behind leaders and arch Glasgow rivals Rangers, needed to win to keep the title race alive with one more game of the season remaining. The man\'s confrontation with Lennon seemed to spark unrest among Celtic fans who appeared to fight with police and stewards. Celtic went on to win the match 3-0 after Kris Commons scored late on to ensure the race for the championship will go to a final day showdown on Sunday. Lennon wrote on his Twitter page: \"Don\'t let what happened to me tonight take the shine off a wonderful team performance... I don\'t walk alone.\" Mjallby said no one could question the manager if he decided to leave after one season in charge of the Hoops. \"We all know that he is a strong character but how much can a guy take? It\'s a dark day for Scottish football. You can never blame him if he is considering going. \"He\'s coped with so much this season and he\'s still been able to work with the team and improve them. \"We will have to wait and see how Neil reacts to this but the rest of us in the dressing room are desperate for him to continue doing his work.\" Scottish police arrested a man and were interviewing him on Thursday. Les Gray, chairman of the Scottish Police Federation, told BBC Radio Five Live there wasn\'t much that could be done to prevent an incident like that. He said: \"This is an individual who has taken it upon himself to attack and it\'s absolutely horrendous. \"But unfortunately from a policing point of view, unless you\'ve got a ring of steel around that park and block the view for quite a number of fans, there isn\'t a lot you can do to prevent it. Last month police revealed they had intercepted parcel bombs intended for Lennon and two other prominent Celtic supporters. Bullets were also posted to Lennon earlier in the season and a suspicious package addressed to him was intercepted in March. Historically, many leading football clubs in Scotland have drawn their support from either the Catholic or Protestant communities in the cities where they are based. Most Celtic fans are drawn from Glasgow\'s Catholic community. Lennon, a Catholic who received death threats while playing for Northern Ireland, where the majority of the population are Protestants, was also beaten up in a Glasgow street while on a night out in September 2008. Scottish Football Association chief executive Stewart Regan and his Scottish Premier League counterpart Neil Doncaster will meet on Thursday to discuss how the man was able to reach Lennon. Doncaster said: \"Like everyone else watching the game I was absolutely shocked and appalled by the incident. There is absolutely no excuse for it,\" . \"It does fall within the SPL\'s remit so we will be investigating it thoroughly. The incident will be investigated thoroughly because we cannot have that type of incident replicated. \"It\'s difficult to get your head around it. It\'s utterly unacceptable for a supporter to get into that situation in the way that they did.\" The Scottish Football Association described the incident as \"wholly unacceptable\". \"The safety of players, club officials and match officials is paramount on or around the field of play, and this clear breach of security is a matter I will be discussing with SPL chief executive Neil Doncaster,\" Regan said.