Police say a 54-year-old Belfast man has been arrested on suspicion of involvement in the Irish Republican Army killing of two plainclothes detectives in a dockside bar nearly 29 years ago.

Nobody was ever convicted for shooting to death 35-year-old Michael Malone and 50-year-old Ernest Carson, who were members of the elite Special Branch intelligence unit. The gunman wounded two others — a police sergeant and a civilian playing pool — when he opened fire on Aug. 26, 1987, inside the since-closed Liverpool Lounge.

Police arrested the man Wednesday. They continue to investigate hundreds of decades-old killings from the Northern Ireland conflict, which has claimed nearly 3,700 lives since 1969.

The outlawed IRA killed nearly 300 police during its failed 1970-1997 effort to oust Northern Ireland from the United Kingdom.