Egypt's tourism ministry has called in experts from abroad to investigate a series of shark attacks off the Red Sea resort of Sharm el-Sheikh.
A 70-year-old German woman was killed on Sunday, just days after four other tourists were injured.
Officials have posted signs along the beach warning people not to go into deep waters, but some tourists are braving the waters close to shore.
There are fears the shark attacks could hurt Egypt's lucrative tourism trade.
Rare attacks
Tourists described in graphic detail how the waters went red as the shark attacked the elderly German woman out snorkelling in a supposedly safe area just 20m (65ft) from the shore.
The woman had died immediately after the attack, in which she was reportedly bitten on the thigh and arm, Egyptian officials have said.
International shark experts are now on their way from the US to help deal with this exceptionally rare series of attacks, the BBC's Jon Leyne reports from Sharm el-Sheikh.
After last week's attacks - in which three Russians and a Ukrainian were mauled - Egypt's environment ministry caught and killed two sharks, and displayed a photo of them, both Oceanic White Tips.
But divers and conservationists who compared the picture with one taken shortly before one of the previous attacks, said it was not the same shark.
Already there has been criticism of the Egyptian government for what some divers say is just a random cull of sharks giving the false impression it was safe to resume water sports, our correspondent says.
Shark experts and local observers have offered a number of possible explanations for the attacks. Some say overfishing in the Red Sea may have driven sharks closer to shore.
Meanwhile, some said predatory sharks could have been drawn to the area after a ship carrying Australian sheep and cattle for sacrifice during last month's Muslim festival of Eid al-Adha dumped the carcasses of animals which had died during the voyage. BBC News
