The homemade bomb went off Sunday evening in Cairo's Khan al-Khalili bazaar, a maze of stalls and cafes popular with tourists. The Health Ministry said most of the injured were French tourists, although three Saudis and a German, as well as four Egyptians, were also wounded. Nineteen remain in hospital.
Police said the bomb was placed underneath a bench on a busy square, and was filled with pieces of metal and nails. They said a second bomb had been found nearby and defused.
No one has claimed responsibility for the blast.
The Muslim Brotherhood, Egypt's largest opposition group, condemned the bombing.
"The Muslim Brotherhood considers that this act goes against the principles of Islam," the organization's leader Mahdi Akef said, adding that the group sought change and reform though peaceful, legal means.
A similar bombing in Cairo's historic heart in 2005 killed two tourists from France and one from the United States, and injured 18 other people, but incidents have been rare since and tourist numbers had been on the rise.
