Egyptian police have arrested three people in connection with a bomb attack in a busy Cairo market, which killed a French teenager and wounded at least 21 others.
Investigators were hunting for clues on Monday after cordoning off the area close to the Hussein mosque, one of the capital's most revered shrines.
"Three people there were arrested on the site as suspects after the attack," a police official said.
"Others are being questioned as witnesses."
Egyptian, French, German and Saudi nationals were injured during the blast on Sunday night in the popular Khan el-Khalili bazaar.
Police said initial evidence suggested a small explosive device, such as a hand grenade, had been thrown from an overlooking balcony.
Earlier reports had said bombs were planted under a seat near a cafe just outside the al-Hussein Hotel.
Motives unclear
The motive for the attack remains unclear and no one has claimed responsibility.
Police later detonated a second device without causing any injuries.
Blood stains could be seen in the front courtyard of the mosque, next to the famed bazaar.
"I was praying and there was a big boom and people started panicking and rushing out of the mosque, then police came and sealed the main door, evacuating us out of the back," Mohammed Abdel Azim, who was inside the mosque at the time, said.
Amr el-Kahky, Al Jazeera's correspondent in Cairo, said some analysts had suggested a link to Israel's offensive against Gaza last month, in which Egypt was criticized in the Arab world for not opening its Rafah border crossing with Gaza and not doing enough to help the Palestinians.
PHOTO CAPTION
Egyptian policemen secure the site of an explosion in Cairo.
Al-Jazeera