Internment in Northern Ireland was the arrest and detention, under the authority of the Special Powers Act, of targeted Irish republicans. The first of some 450 arrests began as the Regular Army launched Operation DEMETRIUS in the early hours of 9 August 1971. The introduction of internment was accompanied by a predictable state of civil unrest. While the Regular Army dealt with the internment action and subsequent civil disorder, the battalions of The Ulster Defence Regiment were ‘called out’ to take over responsibility for Key Point guards, mobile patrols and vehicle check points (VCPs).

During the first night of internment, just as darkness was falling, a patrol from the 6th Battalion The Ulster Defence Regiment’s Strabane company was carrying out a VCP near the Clady Bridge border crossing in County Tyrone. Private Winston Donnell was deployed as the traffic sentry and as a car approaching from Clady drove towards the VCP, Private Donnell stepped out to signal the driver to stop. The occupants opened fire with Thompson submachine guns and Private Donnell was shot and killed.