A woman contacted police on Thursday afternoon to say an object had fallen from her car at Talbot Park - which she had picked up and moved.The object was discovered to be a "crude but viable" explosive device according to police and was made safe in a controlled explosion by army bomb experts.Chief Inspector Jon Burrows, the Foyle Area Commander, said: "It was an under-car booby trap device."It was a crude device but it was viable and it posed a risk to the woman who drove the car and anyone in the area."Chief Insp Burrows added: "We are keeping an open mind as to the motive and are very keen to hear from the public if they have any information. The woman had no connection with the police service or prison service so I do not think that is a motivation."It is also possible that there were children in the car earlier in the day whenever this device was attached to it."