Fear returns to haunt the people of Northern Ireland who have grown used to peace

They gathered in the name of peace, insisting that there should be no return to the bad old days.

Shortly after midday, several hundred residents of Lurgan, Co Armagh, many of them with young children, crowded around a battered tangle of metal fencing in Kilmaine Street. A week earlier a dissident republican bomb had exploded here, injuring three girls.

Monsignor Aidan Hamill, the priest at St Peter's Church, pleaded with the dissidents for a "change of heart". The crowd applauded, then fell silent. Now they must wait and see if their prayers are heard. So must mainland Britain.

The Observer reveals today that British intelligence believes dissident groups in Northern Ireland harbour hopes of striking in a British city and have identified the Tory party conference in Birmingham this October as a target. According to Patrick Mercer MP, a counter-terrorist expert: "They understand that terrorism means terrorising and they have let it be known that they are interested in mainland targets." The disturbing upsurge in violence in Northern Ireland may not stop at the Irish Sea. Read more