Celtic parcel bombs: Who are the targets?
"Viable" parcel bombs have been sent to Celtic manager Neil Lennon and two high-profile fans of the Glasgow club - Paul McBride QC and former MSP Trish Godman.
Here is a look at the backgrounds of the trio.
Neil Lennon started his long association with Celtic when he was signed from Leicester City in 2000 by then manager Martin O'Neill.
The move was a dream come true for the Northern Irishman, who had grown up supporting the club in his home town of Lurgan, County Armagh.
He enjoyed a trophy-laden career with Celtic and captained the team to the league and cup double in his final season in 2007.
Lennon had short stints with Nottingham Forest and Wycombe Wanderers before returning to Celtic as a coach in April 2008.
He served under Gordon Strachan and Tony Mowbray, before the latter's sacking last year thrust him into the role of manager, aged 38.
His first season in charge has seen the club rebound and compete strongly for honours in the Scottish game - but it has not been without controversy.
Lennon has been banned twice for his touchline conduct - but only after disciplinary procedures by the Scottish Football Association were contested and strongly criticised by his QC, Paul McBride.
Depressingly for the game in Scotland, he has also been targeted by a series of threats - the latest of which involved a "viable" parcel bomb, intended to "kill or maim".
This, however, is only an escalation of previous threats and assaults against the 39-year-old which have plagued his time in Scotland.
He retired from international football in 2002 after barracking and sectarian death threats were made against him.
In recent years, other threats have appeared on the internet, or in graffiti daubed on church walls and outside his home.
Lennon has also been assaulted several times during his stay in Glasgow, most recently in 2008. That attack resulted in two men being jailed.
In January this year, the Royal Mail intercepted packages containing bullets addressed to him and Celtic and Northern Ireland players Niall McGinn and Paddy McCourt.
A suspect package addressed to Lennon was also discovered at a mail depot in Saltcoats in March.
In the history of Scottish football, no other figure has been subjected to such pressures. So why Lennon?
The answer, perhaps, lies in his background in Lurgan, where he grew up as a Northern Irish Catholic who supported Celtic - a club founded by Irish Catholic immigrants to Scotland in 1888.
The sectarian divide which exists in Northern Ireland also has its echoes in Scotland, dating back to mass immigration following the Great Famine.
Celtic's fans are drawn largely, though not exclusively, from descendants of these immigrants.
Their great rivals, Rangers, draw support largely, though not exclusively, from the Protestant community.
Amid the sectarian atmosphere that still permeates the game in Scotland, Lennon has become an easy target for people who irrationally hate what he is - a successful and proud Northern Irish Catholic Celtic supporter.
Paul McBride QC
Paul McBride, one of the highest-profile QCs in Scotland and a well-known Celtic fan, became a figure of controversy after his strong attack on the Scottish Football Association.
He has advised the club and acted for Mr Lennon in a legal capacity on several occasions during disputes with the Scottish football's governing body.
The outspoken advocate is as well known in Scotland's court rooms as he is on the football terraces, due to his involvement in a string of high-profile court cases.
Recently, he represented Tommy Sheridan's wife Gail at the couple's perjury trial, as well as acting for the family of former world rally champion Colin McRae at the fatal accident inquiry into his death in a helicopter crash in 2007.
Mr McBride was also defence counsel to Queen's Park murderer Marek Harcar, the Slovakian who was convicted of raping and killing Moira Jones in Glasgow.
Following a recent and infamous Old Firm match between Celtic and Rangers which was plagued with disorder, Neil Lennon received a ban for his actions, while his Rangers opposite number, Ally McCoist, had an initial two-match ban overturned.
The SFA threatened to sue Mr McBride after he branded the organisation "dysfunctional, dishonest and biased", although it is thought the two sides are looking to resolve the matter outside court.
Mr McBride is also known to take to the political and media stage to talk about Scotland's justice system.
His most high-profile speech in recent times came at the 2009 Scottish Conservative conference, just weeks after he abandoned his lifelong support for Labour to join the Conservatives.
As a former deputy presiding officer of the Scottish Parliament and avid Celtic fan, Trish Godman's political profile may have made her a target.
Mrs Godman last month retired from Holyrood, where she was first elected MSP for West Renfrewshire in 1999.
On her last day as an MSP, before the dissolution of parliament, she was pictured in the main chamber wearing a Celtic football top.
Several days later, a device was delivered to her constituency office in Bridge of Weir, Renfrewshire, where her suspicious staff contacted Strathclyde Police.
Mrs Godman, who brought up three sons as a single mother, has always campaigned hard on equality issues.
After training as a social worker, she went on to work with people suffering from drug and alcohol problems in the east of Glasgow, before life as an elected politician beckoned.
Mrs Godman has been forced to deal with personal issues in the media spotlight before, after her son, Gary Mulgrew - one of the so-called Nat West Three - admitted fraud charges in the US in 2007, in a case relating to the Enron scandal.
She said he was the victim of an "unjust extradition treaty which breaches human rights".
Mrs Godman is married to former Labour MP, Norman Godman, who represented the Greenock area at Westminster from 1983 to 2001.