VALLEY OF THE KINGS, Egypt (Reuters) - A newly found tomb containing five mummies was officially opened in the Valley of the Kings on Friday, the first such discovery since the grave of Pharaoh Tutankhamun was uncovered in 1922.

The mummies were in sarcophagi dating from the 18th dynasty and were surrounded by pots holding food which ancient Egyptians believed would be used in the afterlife, archaeologists said.

The 18th dynasty ruled Egypt from 1567 BC to 1320 BC, a period during which the country's power reached a peak. The tomb was found by a U.S. team from the University of Memphis.

"Since the tomb of King Tut was found in 1922, no major discovery happened in the valley," Egypt's chief archaeologist Zahi Hawass told Reuters Television from the tomb during a media visit to mark the official opening.

The mummies, placed in a chamber at the bottom of a 5 meter (16 foot) shaft, might be royals or nobles moved from their original graves to protect them from grave robbers, he said.

"This is a cachet (of mummies), which means that the ancient Egyptians since the end of the New Kingdom began to take the mummies out of the tombs and hide them," Hawass said.

"We don't really know what kind of people are inside but I do believe they look royal. Maybe they are kings or queens or nobles."

The tomb did not contain the treasures of Tutankhamun's grave, which included items such as the gold death mask of the young Egyptian pharaoh.

The tomb had been covered with the rubble of workmen's huts dating from the latter part of the 19th dynasty, more than 100 years after the tomb was sealed. The U.S. team found the top of the new tomb's shaft while working on those huts.

"When we were about ready to close up that work we just happened upon the top of this tomb," said U.S archaeologist Otto Schaden.

Once the work of conservation and restoration was completed, the mummies and pottery would be moved to the Egyptian Museum in Cairo, Hawass said.

© Reuters 2006