A French tourist was killed and 20 people were wounded in a blast in Cairo's populous al-Hussein district on Sunday evening, the health ministry said in a statement.
The French woman died in hospital of her wounds sustained in the explosion, which happened between the al-Hussein mosque and the Khan al-Khalili bazaar, a tourist attraction at around 6:50 p.m., the statement said.
The injured included 13 French tourists, three Saudis and four Egyptians, the ministry said, adding that one of the injured was in critical condition.
Xinhua reporters at the scene said that some 20 ambulances have arrived and police forces have cordoned off the area. Top security officials arrived at the scene soon after the blast and began an investigation.
Egypt's Nile TV quoted witnesses as saying the explosion occurred after two suspects, hiding in a nearby building, threw two bombs at the crowd. One bomb went off at the scene and another was defused by the police.
But the state-run MENA news agency quoted a security source as saying that the explosive might be hidden under a stone bench in the area.
Egyptian President Hosni Mubarak condemned the attack and ordered prompt treatment for the injured, the news service added.
Meanwhile, the Grand Imam of al-Azhar University Sheikh Mohamed Sayyed Tantawi, Egypt's top cleric, condemned the bombing as a "cowardly criminal act".
"(The blast's) perpetrators are traitors to their nation," the state MENA news agency quoted him as saying, adding that "Islam has nothing to do with such terrorist and irresponsible actions".
Attacks against foreign tourists frequently haunted Egypt, where tourism is major source of revenue contributing 8.5 percent to the GDP. In April 2005, two French tourists were killed and 18 others wounded in a suicide attack in the same area.