Emergency services have warned that the toll could rise.
Authorities were able to enter the nightclub several hours later "once the fire had been extinguished", where they discovered "four bodies", then two others around forty minutes later, Euro News reported.
An hour later, Murcia town hall indicated that the toll now stood at seven deaths and that reconnaissance work was continuing.
“Priority is given to locating the bodies” in the building, a spokesperson for the national police told AFP.
“The investigation has not yet started since the results have not been established. Consequently, there is no preferred lead at the moment,” she added.
Four people were also injured - two women aged 22 and 25 and two men aged 41 and 45 - after inhaling smoke.
According to the mayor of Murcia José Ballesta, who declared three days of mourning in memory of the victims, the fire service mobilized 12 emergency vehicles, 40 firefighters, as well as around twenty police officers.
RHM/PR