Police say two bombs exploded in different locations in the Northern Ireland city of Londonderry Thursday night but there are no reports of injuries.
As police investigate, some politicians are accusing dissidents of the Irish Republican Army of making the attacks in a predominantly Catholic area of west Londonderry.
Dissidents have been linked to similar attacks as a rejection of the IRA's anti violence truce with British officials.
Police say they got a telephone warning 30 minutes before the first blast outside a tourist office.
The second blast occurred as officers were evacuating people, including dozens of seniors from a nearby nursing home.
Police Superintendent Stephen Martin described the bombings as "cowardly and callous."
The French Press Agency says Thursday's bombings occurred on the eve of a court ruling of two IRA dissidents charged with killing two off duty British soldiers in 2009.