An explosive device detection system includes sensors and base station that detect and report on suspected Improvised Explosive Devices (IED) or landmine emplacement activity within a geographic area. When disposed within a geographic area, each sensor forms part of a wireless communications network which allows communication among neighboring sensors. As a sensor detects activity in its proximity, such as activity that indicates emplacement of an IED, the sensor transmits a reporting signal through the network to the base station. The neighboring sensors receive and transmit the reporting signal in a sequential manner toward the base station. Because the reporting signal takes multiple hops toward the base station, the sensors do not require large amounts of power to transmit the signal. Furthermore, the detection system allows detection of IED emplacement within the geographic area as the activity occurs. As a result, the base station can direct mobile response units to take immediate responsive action to prevent detonation of the IED's.