We report on the observations of radar echoes at the lower HF range from the lower part of the ionosphere, below 60 km altitude. The observed echoes are actually seen below and isolated to the generally accepted lowermost ionospheric D region. For the detection of these echoes we employed machine learning techniques for the inspection of 4 years of radar raw data. We derived statistical parameters of their occurrence and hypothesised a connection for galactic cosmic rays as an ionisation source.