attempting to launch talks in the city so that remains a possibility. but i would say a slim one. the most likely suspects are isis linked or isis individuals. they have got quite a way down the park here, peter, they have manageded to make a detonator that has successfully gone on. the luck involved in this is the main charge that would cause the main explosion has not ignited. that has definitely saved lives. obviously the remnants of that device are going to be critical to this investigation as they try to use that in a way as a road map to identify who may have been responsible for this, where they may have received the information on how to go about building this device. how important are those remnants from what we re looking at on the screen right now that included, among other things, christmas lights? reporter: absolutely. that is a kind of standard, if you like, what we call an initiator circuit using the ferry lights or the christmas lights as a hot wire ignitor to