Officials sought to play down the impact of the attacks, which revived memories of the wave of Islamist violence that targeted tourists in the 1990s.

A large police cordon was set up around the world-famous Egyptian Museum, near which a man blew himself up as he jumped off a bridge Saturday, wounding an Israeli couple, an Italian woman and a Swedish man.

Less than an hour later two women - the man's sister and his fiancee - died in an abortive attack on a tourist bus close to the Citadel, another jewel in Egypt's tourism crown.

The involvement of the two women - a first for conservative Egypt - prompted concern about the security implications.

``Normally activists' mothers and wives try to persuade them not to volunteer for suicide operations or take part in attacks for fear of losing them,'' said analyst Hassan Nafea.

``Here we are seeing a new phenomenon totally alien to traditional Egyptian society.''

By Sunday, police had detained over 200 people in swoops on the city's slums and the tourism ministry has set up a crisis cell to monitor developments and make contact with foreign tour operators ``to give them a precise picture of the situation,'' said a spokesman.

Saturday's attacks followed a bombing in Cairo's main tourist bazaar last month that the authorities described as an ``isolated incident,'' with previous attacks having hit the country's tourism-dependent economy hard.

Two French nationals and an American died in the April 7 bombing, and those who died Saturday were reportedly linked to that attack.

In 1997, the worst attack saw 62 people, including 58 foreign tourists, killed in the southern city of Luxor and sparked a ferocious police clampdown that eventually led to the vital sector's rehabilitation.

Tourism Minister Ahmed al-Maghrabi also sought to minimize the impact of the latest attacks impact on the tourism industry, in high season at this time of year.

But Chamber of Tourism president Elhamy Zayat, said it is too early to assess the fallout. ``For the moment we are trying to reassure our operators abroad by telling them exactly what happened and planning for possible cancellations,'' he said.

Despite beefed-up security, Cairo's main tourist centers were all but deserted Sunday, in particular around the Egyptian Museum and the Citadel.

``We're not very reassured,'' said Belgian tourist Anne-Claude Triboulet as small groups of tourists headed past barricades and into the famed museum.

Security has been tight at the museum's main entrance since a tour bus was firebombed in 1997, killing nine German tourists and their Egyptian driver.

But now police surround the entire building, home to countless priceless pharaonic artifacts.

AGENCE FRANCE-PRESSE