A network has been constructed along Crete island (Greece) for earthquake prediction using seismogenic electromagnetic emissions. The network consists of four observation points. Each observation point has: (a) loop antennas tuned to 3 and 10 kHz. (low frequencies-LF). The final stage of the antennas is an RMS to DC converter. Thus the output of the receiver is a DC voltage that is proportional to the power spectrum density ΦH of the magnetic field that excites the antenna, (b) dipoles to observe variations in 41 and 53 MHz (high frequencies-HF). In this stage the DC output is proportional to the electric field which appears in the antenna. In the present contribution recordings of the electromagnetic anomalies that precede earthquakes during the last three years are presented. The experimental results indicate the presence of radioemissions, associated to shallow and intermediate depth earthquakes in the vicinity of Crete island. It is concluded that the electromagnetic variations appear to follow an invariant time pattern (i.e. LF variations - HF variations - Earthquake event).