A shark tore the arm off an elderly German tourist at an Egyptian Red Sea resort, killing her almost immediately, security and diving officials said Sunday, only days after sharks badly mauled four other European tourists in the waters.The German was swimming in the waters off Sharm el-Sheikh, a famed diving and vacation resort in the Sinai peninsula, when the shark attacked, Egyptian security officials said, speaking on condition of anonymity because they are not allowed to brief the media."It was definitely a shark attack," said Hesham Gabar, the head of Egypt's Chamber of Diving and Water Sports. The German Embassy in Cairo could not be immediately reached for comment.Sunday's deadly attack comes after oceanic white tip sharks mauled three Russians and a Ukrainian tourist last week, also off the coast of Sharm el-Sheikh. In one of those attacks, a shark bit off an elderly woman's hand and tore off another woman's leg.Egyptian authorities closed Sharm el-Sheikh's beaches following those attacks, and on Thursday the Environment Ministry said two sharks suspected of mauling the four tourists were caught.Authorities then reopened Sharm el-Sheikh's beaches Saturday after divers from the Chamber of Diving and Water Sports and the Environment Ministry scoured popular diving sites in an effort to ensure they were safe.The Environment Ministry also ordered authorities to beef up security measures at beaches in the area. requiring diving centers to provide staff to supervise beaches and watch the waters for sharks.Environmentalists warned that the string of recent attacks is likely a result of the Red Sea's declining ecosystem. Gabar, the head of the CDWS, said he's seen a jump in the number of sharks off Egypt's Red Sea coast, which he said could be caused by overfishing.The spate of shark attacks in Sharm el-Sheikh — one of Egypt's main beach resorts that attracts millions of foreign vacationers annually — could deal a blow the country's tourism industry, a vital source of income.Beach tourism is believed to contribute some 66 percent of Egypt's total income from tourism which is expected to reach $12.3 billion by end of the current fiscal year ending 2011, Tourism Minister Zohair Garanah was quoted as saying in state-owned Al-Gomhoriya daily.In September prime minister predicted the country's economy could grow by six percent in the current fiscal year, boosted by strong first quarter results in tourism.