Egyptian police are questioning three suspects over the bombing of a Cairo market that killed one person and injured 20 others, officials say.
They were detained near the market shortly after the blast, police said.
The explosion happened at an open-air hotel cafe packed with tourists in the Khan al-Khalili area - a major attraction and home to a prominent mosque, the BBC reports.
French President Nicolas Sarkozy has expressed "deep sorrow" at the death of a French teenager in the blast.
Police said they thought the device had been thrown from a balcony. It is not yet known who was responsible.
There have been conflicting reports the bomb, which is believed to have been home-made, may have been left under a bench.
Those injured in the blast included more than a dozen French nationals, four Germans and three Egyptians, according to police. Six are thought to be in a serious condition.
The French foreign ministry confirmed the death of one of its citizens, a 17-year-old girl.