Five men named in writs as being involved in the Omagh bombing will be "strenuously denying" the allegations, according to republicans in Dundalk, Co Louth.
Solicitors acting for the Omagh relatives yesterday served writs on Mr Seamus Daly, Mr Seamus McKenna, Mr Mickey McKevitt, Liam Campbell and Colm Murphy.
The families are seeking damages from those they claim were involved in the "Real IRA" bomb which killed 29 people in August 1998.
At different points in recent years each of the five defendants has denied any involvement.
Campbell is serving five years for membership of an illegal organisation.
Murphy, a builder and publican, was sentenced to 14 years imprisonment in January for conspiring to cause the Omagh bomb.
It is understood a hearing will take place at Belfast High Court later this year. Mr Rory Dougan of the 32 County Sovereignty Movement last night said the men would be protesting their innocence.
"This is a blatantly political stunt designed to blacken the names of these men.
"Four of the men have never been charged or convicted of any offence in connection with Omagh. The conviction of the fifth man, Colm Murphy, has been seen as very dubious by a range of media and legal experts and Mr Murphy is appealing his conviction. These are five innocent men who will all be strenuously denying the allegations."
A solicitor acting for the relatives, Mr Jason McHugh, served writs at the last known addresses of Mr Seamus Daly and Mr Seamus McKenna in Dundalk at 6.45 a.m. Neither answered the door.
One writ was handed to Mr Daly's father through a window and the other was posted through Mr McKenna's letter-box. Mr McHugh was accompanied by gardaí at his request.
A legal assistant for the families, Ms David-Aire Horsford, travelled to Portlaoise Prison to serve writs on Mr Mickey McKevitt, Liam Campbell, and Colm Murphy.
She personally handed writs to Mr McKevitt and Campbell but Murphy refused to meet her, according to media reports. Mr Michael Gallagher, whose son Aidan was killed in the bombing, waited outside the prison.
Mr McKevitt is currently awaiting trial for directing terrorism. He is denying the charges.