(CNN) -- A German woman died Sunday after being attacked by a shark in waters off Sharm el-Sheikh, Egypt, in an area where three snorkelers were injured and two sharks were caught last week, officials said.
Egypt's tourism ministry has decided to close the Sharm el-Sheikh beach until the shark responsible for Sunday's attack is found, according to the nation's Interior Ministry.
Jochen Van Lysebettens, general operations manager of the Red Sea Diving College in Sharm el-Sheikh, said employees at the Hyatt Regency resort told him the attack happened about noon (5 a.m. ET) in a protected swim area off the resort. Van Lysebettens has three dive-instruction operations in the area, including one at the Hyatt Regency.
The 70-year-old woman, a regular guest at the resort, was snorkeling near a reef when she was attacked, he said. She called for help, and a lifeguard brought her to shore, but she had lost too much blood and resuscitation efforts failed, Van Lysebettens said. The woman's arm and leg were severed, he said.
After the Sunday incident, the Chamber of Diving and Watersports called on its members in the region "to stop any snorkeling activities happening from any boats or shore." The chamber is under the umbrella of the Egyptian Tourist Federation.
Van Lysebettens said all tourists were ordered to stay out of the water at least through Monday. The dive community is organizing volunteer expeditions to find the shark, he said, and about 40 people will search Monday.
On Friday, two sharks were caught and killed near the South Sinai National Park on the Sharm el-Sheikh coast, according to the Chamber of Diving and Watersports.
The chamber said that as of Friday, the condition of three injured snorkelers -- two Russian women and a man from the Ukraine -- were unchanged. One of them was critical, the chamber said in a statement, but did not say which one. The three were attacked in a 24-hour period November 30 and December 1, the chamber said.
Van Lysebettens said he is not a marine biologist, but many have speculated an oceanic white-tipped shark was responsible for the German woman's death, as well as the other attacks. Divers are upset because the two sharks killed Friday are thought to be innocent. They were a mako shark and another oceanic white-tipped shark -- which did not match pictures taken by someone accompanying one of the injured snorkelers, he said.
Officials at the national park did not provide details on "why the animals could not be relocated to remote waters as was previously suggested," the chamber's statement said, adding it "does not wish to see any harm to any further sharks."
Exploratory dives were taking place on Friday, Van Lysebettens said.
Officials are not sure what triggered the feeding behavior, described as highly unusual.
"This incident has clearly shocked our community, and the CDWS is continuing its investigation into why this may have happened," Hesham Gabr, head of the Chamber of Diving and Watersports, said in the statement. "It is clear from our initial discussions with shark behavioral experts that this highly unusual spate of attacks by an oceanic white tip shark was triggered by an activity, most probably illegal fishing or feeding in the area."
Several divers in the area saw carcasses of dead sheep in the water last week, Van Lysebettens said. It's not known how they got there, he said, but they could have washed out to sea or fallen off a boat. The shark may have been attracted by the carcass, he said, and could now be attacking slow-moving things on the water's surface.
CNN's Brian Walker and Karen Smith contributed to this report.