The tomb was located at the bottom of an 11m deep shaft, announced Egypt’s top archaeologist Zahi Hawass.
Eight of the mummies were in sarcophagi, while the rest had been placed in niches along the wall.
Hawass described the discovery as a “storeroom for mummies”, dating to 640 BC and the 26th Dynasty, which was Egypt’s last independent kingdom before it was overthrown by a succession of foreign conquerors beginning with the Persians.
The tomb was discovered at an even more ancient site dating back to the 4,300-year-old 6th Dynasty.
Most of the mummies are poorly preserved and archeologists have yet to determine their identity or why so many are in a single room. One of the sarcophagi is made of wood and bears the name Badi N Huri, but no title.
“This one might have been an important figure, but I can’t tell because there was no title,” Hawass’s assistant Abdel Hakim Karar said.
He added that the rest of the sarcophagi — including four which are tightly sealed — have yet to be opened.
Karar added that it was quite unusual for mummies of this late period to be stored in rocky niches.
“Niches were known in the very early dynasties, so to find one for the 26th Dynasty, is something rare,” Karar said.
Excavations have been ongoing at Saqqara for 150 years, uncovering a vast necropolis of pyramids and tombs dating mostly from the Old Kingdom, but including sites as recent as the Roman era.
In the past, excavations have focused on just one side of the two nearby pyramids — the famous Step Pyramid of King Djoser and that of Unas, the last king of the 5th Dynasty. The area where the present tomb was found, to the south-west, has been largely untouched by archeologists.
But despite the years of excavation, new finds are constantly being made. In December last year, two tombs were found near the discovery. The two were built for high officials — one responsible for the quarries used to build the nearby pyramids and other for a woman in charge of procuring entertainers for the pharaohs.
In November, Hawass announced the discovery of a new pyramid at Saqqara, the 118th in Egypt, and the 12th to be found just in Saqqara. According to Hawass, only 30% of Egypt’s monuments have been uncovered, with the rest still under the sand.