Police chief Humberto Nunez said on Sunday that bodies were still being removed.
Firefighters at the scene said the accidental explosion of gas canisters in a kitchen in the supermarket was the likely cause of the blaze.
A discotheque opposite the supermarket was being used to deposit dozens of bodies.
The disaster appears to have stretched the emergency services of the landlocked country, one of South America's poorest nations.
Local television showed firefighters desperately trying to plug holes in leaking water hoses with the soles of their boots.
Local media has called on citizens to donate basic supplies, such as gloves, to hospitals.