VENEZUELA: Unknown Morse code broadcast on 5990v Khz heard in Mérida,

Hi everyone,
Last night (30-01-2011) I was listening to the radio when by the way I found an interesting broadcast on 5990v Khz broadcasting a Morse code transmission between 01.15 and 01.39 UTC.
What really called my attention was that I wasn't using SSB neither USB because it was with my simple JWIN JXM 14 receiver and a four meters long wire. At least for me, it is unusual to find stations broadcasting Morse code on the normal broadcast bands and less by no using any lateral bands.
I recorded the station. Reception was aceptable. Very low interference but some noise. No fading.
I have been wondering if it is some numbers station which was broadcasting Morse at the time. Could be the Cuban station "Atención"?
So if someone of you has listened in to this kind of broadcast, if someone of you have an idea, please let me know what it is.
Thanks beforehand!

Your friend,

Leonardo Santiago
Mérida
Venezuela.