The bomb went off at around sunset in a crowded outdoor cafe in a plaza outside the city's historic Hussein mosque, one of the largest and holiest in the city.
Officials say 19 other French teenagers were among the wounded, as were three Saudis and an Egyptian. Three of the teenagers were in serious condition Monday, reports the Associated Press. Confusion over the death toll immediately followed the attack, as the Monitor reported here on Sunday.
The bomb was the first in Cairo since April 2005. No group has yet claim responsibility for the attack, although on Sunday police arrested three suspects.
"Three people there were arrested on the site as suspects after the attack," a police official told Agence-France Presse. "Around 15 others are being questioned as witnesses."
Shaken by the bombing, finger-pointing across the Egyptian capital has already begun.