An American tourist died Friday from wounds sustained in a bomb blast that rocked a Cairo (search) bazaar popular with foreigners, a U.S. Embassy spokeswoman said, taking the death toll in the Egyptian capital's first such attack in seven years to three.

Micaela Schweitzer-Bluhm (search) said another three Americans were among the 18 people injured in Thursday's explosion in a packed bazaar area in Cairo's old city, which also killed a French woman and another person whose identity has not yet been revealed.

"One of the Americans has died as a result of the wounds from the bombing early this (Friday) morning," Schweitzer-Bluhm said. She provided no further details.

Egyptian Tourism Minister Ahmed El Maghraby (search) confirmed that an American male aged in his 20s had died in hospital from his injuries.

Another three Americans, four Egyptians, and a Frenchman and his wife remain in hospital, he said, adding that the Frenchman is in a critical condition. Another French person, one Turk and several Egyptians have been released from hospital. Many of the wounded suffered severe wounds from nails packed in the bomb.

The Interior Ministry also said an Italian was injured, but Italian diplomats leaving the hospital later said there were no Italians among the casualties and there was no explanation for the discrepancy.

El Maghraby said he had no details on who was responsible for the attack, but added that similar attacks in the past have "turned out to be the act of one individual or a very small group of people."

While condemning the attack, El Maghraby also called for calm and said tourists should not be scared away from traveling to Egypt.

"These are actions totally unacceptable by any human being, but these events do happen and life has to continue," El Maghraby said while visiting the wounded people in a Cairo hospital. "We should not be intimated and lose our right to free movement."

On Friday, hundreds of police sealed off a 400 meter (yard) stretch of road lined by two and three story rundown warehouses and stores where the blast took place, interviewing shop owners for clues.

Blood stains remained on the road and on the second story wall of a building in the al-Moski bazaar, a maze of narrow alleys with shops selling jewelry, souvenirs and clothes connected to the biggest tourist souq, Khan al-Khalili.

Amin al-Laban, a 51-year-old spice store owner in the street where the blast occurred, said his 22-year-old son, Mohamed, was injured in the massive explosion.

"The blast was so big that I thought that the building above my shop collapsed, when I came out to check on Mohamed, I could not see anything from the black dust," the elder al-Laban said.

The U.S. Embassy in Cairo issued a warden message warning Americans to stay away from Khan al-Khalili, the sprawling bazaar area, and to use prudence elsewhere in the city.

Witnesses said a man on a motorcycle appeared to set off the blast, which police say initial investigations suggested the explosive was a homemade nail-packed bomb that went off prematurely

Brig. Gen. Nabil al-Azabi, head of security in Cairo, said the second person killed, whose body was severely mutilated, may have been the man carrying the bomb. Officials warned the death toll could rise, with several of the wounded in critical condition and body parts still to be identified.

The attack follows a long period of calm since security forces suppressed Islamic militants who in the 1990s carried out bombings and shootings against tourists in their campaign to bring down the government.

The last significant attack on tourists in Cairo was in 1997, a year when another 62 were killed in another attack in Luxor. Last October, explosions hit several hotels in the Sinai Peninsula, including one in the resort of Taba, killing 34 people. Egyptian authorities say that attack was linked to Israeli-Palestinian violence.

There has been no claim of responsibility for the attack. Police said they have taken two people in for questioning and were investigating a motorcycle found near the scene with nails scattered on the ground around it.

Witnesses were unclear if the man on the motorcycle was a suicide bomber or threw an explosive. The blast site is in the heart of Islamic Cairo near al-Azhar, one of the most prestigious Islamic institutions in the Sunni Muslim world, in Cairo's old city.