People in the Northern Irish city of Londonderry have been marching to remember Bloody Sunday, the day British troops killed 14 unarmed civilians.

The incident in 1972 took place during the height of the Troubles - a conflict pitting mostly Catholic Irish nationalists or republicans, against pro-British, mostly protestant unionists.

The march also comes a week after suspected dissident republicans detonated a bomb in Derry.

Police fear fringe paramilitary groups will exploit the threat of a hard border in Ireland due to the ongoing Brexit negotiations.

Al Jazeera's Catherine Stancl reports from Derry, Northern Ireland.