The monument, to Jim Lynagh and Padraig McKearney, two of eight IRA men killed in 1987 as they launched an attack on the RUC station in Loughgall, was completely destroyed in the mystery attack earlier this week.
The structure, a large memorial encased in ornate granite and surrounded by a wrought iron fence, was erected in 2007 at Drumfurrer in Co Monaghan close to the border with Tyrone.
It's destruction has been described as a 'horrendous act of disrespect and disregard'.
A statement issued on Wednesday night by Mairead Kelly and Roisin Ni Cheallaigh on behalf of the Loughgall Truth and Justice Campaign stated: "This evening we were alerted to the devastating news regarding the desecration of the monument at Drumfurrer. Such a horrendous act of disrespect and disregard not only to the memory of the Volunteers but also an assault on the families of these men.
"We are truly shocked and astounded that anyone would remove, in its entirety, a monument that was not only a beautiful and truly fitting memorial to Volunteer Jim Lynagh and Volunteer Padraig McKearney but also a place where families and friends could go to reflect and pay their respects to the men who had fought and died for their country.
"Tonight we extend our sympathies and respect to the families of Jim and Padraig and to the extended families of the men who died at Loughgall. To do this to any of the Loughgall families is to do it to us all. It is a very upsetting and sad time but our memories and thoughts cannot be erased. We will remember our heroes with the respect and dignity that they deserve."
A Go Fund Me page has been set up in order to raise funds to rebuild the memorial.