The chambers, which were cut out of rock, belonged to a middle-class family who probably lived during the Ptolemaic period (305-30BC).
Their identities are still unknown, but the mummification method suggests they held important or prestigious positions.
Mostafa Waziri, secretary-general of the Supreme Council of Antiquities, said the team who made the discovery at the Tuna el-Gebel archaeological site had not found names written in hieroglyphics.
Some were decorated with “demotic handwriting” – a form of ancient Egyptian script used by ordinary people.
Pottery, papyri and colourful mummy cases were also unearthed.
Visitors, including ambassadors from several countries, gathered at the discovery site where 40 of the mummies were exhibited during the announcement ceremony.
Some of the mummies were found wrapped in linen while others were placed in stone coffins or wooden sarcophagi.
The archaeological finding was the first of 2019 and came about through a joint mission with the Research Centre for Archaeological Studies of Minya University.
Egypt has made a series of archaeological finds recently, and has been heavily promoting them to revive its tourism industry – a staple of its economy that was decimated by the chaos following the 2011 uprising.
Reuters and AP contributed to this report
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