There was no obvious RUC reaction on the streets of Derry last night following the London bombing and the announcement of the end of the IRA ceasefire.
However, a high ranking RUC officer in the north west said that the news of the explosion had come as a great surprise to him and his police colleagues.
"I just do not know if there was any Special Branch inkling about this, but given the fact that it seems to have taken the Sinn Fein leadership by surprise, I would have thought that the Special Branch are as surprised as anyone else.
"There was a meeting of the Police Federation all day today and there was no mention of a possible ceasefire collapse at that meeting. No indication whatsoever was given at the meeting and if there were any concerns within the force we would have expected to have heard about them at that meeting.
"Police officers will, I expect, be told to resume the situation of alertness they were used to before the ceasefire".