Police in Northern Ireland were on full alert today amid fears of an escalating terrorist campaign by dissident republicans.
A faction opposed to the peace process was blamed for last night's bombings in and around the centre of Londonderry and even though nobody was hurt, police said the terrorists were prepared to take whatever chances they thought necessary to cause destruction.
The visitor and convention bureau - Derry is host city for next year's UK City of Culture - and DHSS offices were damaged by two explosions following a telephone warning.
Dozens of people, including elderly residents in sheltered accommodation, had to flee their homes.
Police said either the Real IRA - the organisation which bombed Omagh in August 1998 killing 29 people - or a group called Oglaigh na hEireann is likely to have been responsible.
The level of terrorist activity in Northern Ireland over the last six months has been relatively low, but police are now on full alert - especially over the coming days - amid fears there could be a dramatic escalation in the campaign.
Derry police chief superintendent Stephen Martin said: "I can't understand their logic or what they hope they can contribute. They appear to be cavalier in terms of the risk they are prepared to take.
"When you carry bombs into an urbanised environment, they will know the risk they have taken. They will have scurried off and got themselves safe before making their phone call. They'll have left the bombs inside bags and you could have had inquisitive young people; people walking their dog or stopping for a chat cut to pieces with bombs going off prematurely."
He added: "The great threat to these groups is normality and the more normalised society we can create is what they fear most."