Five witnesses are under threat following the mob murder of Catholic youth worker Kevin McDaid, the High Court in Belfast has heard.
A judge was also told up to 30 people left a pub to go on a sectarian rampage through a part of Coleraine where the victim lived.
It was claimed the crowd launched an orchestrated assault on the Heights area because Irish tricolour flags had been erected.
Details were disclosed as one of the men accused of Mr McDaid's murder applied for bail.
Christopher McDowell, of Glebe Avenue, Coleraine, is among nine people charged in connection with last month's attack, after Rangers beat Celtic to claim the Scottish Premier League title.
The 33-year-old is also accused of the attempted murder of another local Catholic man, Damian Fleming, who was beaten and seriously injured.
'Warnings'
During the hearing, a prosecution barrister confirmed that since the murder two witnesses have received police warnings that their lives are in danger.
A further three have also claimed to have received direct threats telling them to leave the Coleraine area.
It was also revealed police were continuing house to house inquiries amid concerns of possible retaliatory attacks.
A defence barrister disputed the murder charge against his client, Mr McDowell, pointing out that a heart attack appeared to have caused Mr McDaid's death.
The judge, Mr Justice Treacy, adjourned the bail application to allow him time to study transcripts of police interviews with the accused.
© UTV News