A number of lines of inquiry are being investigated by gardaí after a review of the investigation into the 1972 Belturbet bombing that killed two teenagers.
The families of the victims welcomed the “significant” development, and urged anyone with information to come forward.
A car bomb exploded outside Farrelly’s Bar and McGowan’s Drapery on the main street of Belturbet, Co Cavan after 10pm on December 28th, 1972, killing Patrick Stanley (16) and Geraldine O’Reilly (15) instantly and leaving eight others injured.
In a statement issued on Wednesday, gardaí said a senior officer has been appointed to lead the investigation with an incident room at Ballyconnell Garda station.
The Pat Finucane Centre, along with the O’Reilly and Stanley families, welcomed the development and urged people to come forward.
The human rights group said the teenagers had lost their lives in a no-warning loyalist bomb attack, adding: “We have supported the two families for almost 20 years and, at last, we have this very significant and positive development in the case.
“We appeal for anyone with information to contact the Gardai,” it said.
Patrick, from Clara, Co Offaly, was a keen hurler, footballer and soccer player.
He had applied for a cadetship in the Army but was temporarily employed by local businessman Pat Jennings as a helper on a Calor Gas delivery lorry.
On the night of the explosion there had been a problem with the lorry, meaning he and the driver decided to stay in Belturbet overnight.
When the bomb exploded, Patrick was in the public phone booth on the main street calling his parents, Teresa and Joe, to tell them he would not be home.
Geraldine was from Drumacon in the Belturbet area, and the youngest of seven. She had completed her Group Certificate examination the previous June, gaining six honours and intended to take up a career in nursing.
She had come into town with her brother Anthony to get food, and was in a restaurant when the bomb exploded in a car parked opposite.
The incident room at Ballyconnell Garda station can be contacted on 049-9525580, or contact can be made through the Garda Confidential Line on 1800-666 111 or Crimestoppers on 1800-250 025.