(Warning: Loud) What is this sound in the MW band?

Heard this sound at about 1200 kHz AM using an analog consumer radio in eastern Czech Republic. (Could be a superheterodyne mirror from another band, though.) What is this? I don't have an SDR or other ham equipment, this is just a mic recording.

I thought it could be useful to drive mice out of a garden shack but it was gone the next day.