 After peace was declared in 1921 the internees were released but it does appear that their ordeal did not necessarily end after leaving as evidence exists that a train carrying released prisoners from Ballykinlar was attacked at Thurles, County Tipperary, injuring three Sinn Féin passengers and several members of the crowd.In 1971, during Operation Demetrius, which reimposed internment in Northern Ireland, Ballykinlar became a Regional Holding Centre for internees.In World War I the 36th Ulster Division formed from the Ulster Volunteers did much of its training at Ballykinlar.