Celtic have vowed to "remain strong in the face of intimidation" after it emerged that two viable parcel bombs had been sent to manager Neil Lennon.
Paul McBride QC, who represented Lennon in his recent disciplinary dealings with the Scottish Football Association, and MSP Trish Godman, a Celtic supporter, have also been targeted and Strathclyde Police revealed the packages were "designed to cause real harm to the person who opened them", but all four were intercepted beforehand.
Celtic chief executive Peter Lawwell appealed to supporters to stay calm and only respond through support for Lennon, who has been the subject of tight security measures since another item, initially thought to have been a hoax, was intercepted by Royal Mail staff on March 4.
Lawwell said: "Neil Lennon is a football manager who simply wants to carry out this role to the best of his professional ability.
"However, in this horrific ongoing campaign, he and other Celtic personnel continue to be the subject of repeated threats and intimidation.
"It is an intolerable state of affairs which must end. Celtic, from our inception, has been a club open to all. We enjoy friendship and respect throughout the world yet, here in Scotland, we are caught up in these vile events."