Lennon was last night the subject of an alleged assault at Tynecastle and a package containing ammunition was found at Celtic Park today.

In a statement, Lawwell said the Tynecastle incident "brings shame on Scottish football and again highlights the fact that Scottish society must address fundamental and serious issues which lead to outrages of this kind".

He added: "It is intolerable that any football club, or individual, going about their lawful business in the name of sport should be subjected to this ongoing campaign of hatred and intimidation.

"This is Scotland's shame and it is high time Scotland addressed it."

Lennon has had round-the-clock security since March 4, when the first of two parcel bombs addressed to him was intercepted at a Royal Mail sorting office. Two men were arrested today in Ayrshire in connection with that police inquiry.

The package found at Celtic Park today contained a bullet and is believed to have been addressed to Lennon, the second time such an item has been sent to the former Northern Ireland international this year.

A man later appeared in court charged in connection with the Tynecastle incident, which took place after Gary Hooper scored the second goal in Celtic's 3-0 Clydesdale Bank Premier League win.

John Wilson, 26, of Edinburgh, was charged with breach of the peace aggravated by religious prejudice and assault aggravated by religious prejudice. He made no plea and was remanded in custody.

Lawwell called for former Celtic captain Lennon to be given the same licence as other managers to carry out their jobs.

"It is intolerable that any football club, or individual, going about their lawful business in the name of sport should be subjected to this ongoing campaign of hatred and intimidation," he said.

"This is Scotland's shame and it is high time Scotland addressed it.

"Since moving here a decade ago, Neil Lennon has had to endure prejudice and violence both as a player and manager, having suffered no such problems elsewhere.

"In doing so, he has displayed a strength of character and resilience which deserve respect from all who oppose the campaign of intimidation against him.

"He is a man who is proud to be the Celtic manager and is someone who simply wants to be able to carry out his role in the same way as every other football manager can.

"Clearly, Neil will continue to receive every support and protection from Celtic Football Club."

Lawwell also referred to an incident which led to seven people appearing in court charged with possessing an imitation firearm.

Lawwell said: "Apart from last night's events, this week alone we have seen seven people arrested at our training ground following an alleged firearms incident and I can also confirm that this morning another package arrived at Celtic Park which appears to contain ammunition.

"This has been removed and taken by police for further forensic tests.

"We are the only club to be the subject of such vile, sustained and relentless attacks."

Lawwell added: "We are deeply appreciative of the intensive police efforts to address the criminal offences that have come to light.

"All right-minded people will surely condemn these actions but, as a society, we must also address the underlying factors that lead to such behaviour."

Lennon was said to have been "shaken" by events at Tynecastle.

But, despite such off-field concerns, Lennon was focused on his team's success.

Two goals from Gary Hooper and a Kris Commons strike kept alive Celtic's SPL title hopes.

Celtic now need a better result against Motherwell on Sunday than Rangers achieve against Kilmarnock.

The Celtic boss wrote on his Twitter page: "Don't let what happened to me take the shine off a wonderful team performance... I don't walk alone."

Lennon's agent, Martin Reilly, later insisted his client would not quit in the wake of the incidents.

Reilly told STV: "First and foremost, Neil is shaken about the whole thing, but he won't be driven out of Scotland.

"Neil is concentrating on trying to win the SPL and the team has a Scottish Cup final to contest.

"At the end of the season I will sit down with Neil and if there are things that he's unhappy about then I will try and fix them. He won't throw in the towel."