Northern Ireland police say they have arrested three suspected Irish Republican Army dissidents over a car bomb that was planted on a road junction in Londonderry.
The alert snarled traffic in Northern Ireland's second-largest city from Monday afternoon until early Tuesday as police removed the bomb.
The area's police commander, Chief Inspector John Burrows, declined to speculate on the dissidents' target or why the bomb failed to explode. He said police evacuated four nearby homes overnight.
Police say they are interrogating three Londonderry men aged 46, 49 and 54 about potential links to the bomb.
Several IRA splinter groups still seek to force Northern Ireland out of the United Kingdom. They reject the IRA's 2005 decision to disarm and renounce violence.