Three US shark experts head to Egypt after a spate of attacks in Sharm el-Sheikh leaves one tourist dead and four injured

Three US shark experts are flying to Egypt to try to help explain what is behind a series of shark attacks that have killed one tourist and injured four others over the past week.

As British holiday companies cancelled all watersports and boat trips in the Red Sea resort of Sharm el-Sheikh, there were unconfirmed reports that swimmers were forced to flee from the water after a shark was spotted close to the beach.

Shark attacks at Egypt's Red Sea resorts are rare, and the attacks on the southern tip of the Sinai peninsula are believed to involve a single oceanic whitetip shark.

Snorkelling and most watersports have been suspended at the resort following the death yesterday of a 70-year-old German woman. However, the authorities are allowing experienced divers into the water from tomorrow.

The Egyptian authorities are at a loss to explain the attacks, but theories yesterday ranged from the sharks being attracted by dead animals dumped in the water to the bizarre claim that Mossad, the Israeli secret service, put the man-eating shark in the water to try to undermine the Egyptian tourism industry.

The trio of experts is expected to arrive over the next two days, with a fourth advising from his US research centre. A Swedish vessel is also surveying the waters around Sharm el-Sheikh to track shark movements.

Yesterday's death occurred the day after the authorities lifted a 48-hour ban on holidaymakers entering the water, following attacks on three Russians and a Ukrainian.

Officials, who are likely to face criticism for allowing the beaches to reopen, had said they were confident the capture and killing of two sharks on Thursday had eliminated the threat to swimmers. However, one British couple said their group of snorkellers had to scramble for safety after a large shark circled swimmers on Saturday.

Egypt's Chamber of Diving and Watersports (CDWS) said the shark experts would "form an advisory team to try to assess and advise on the best course of action following the shark attacks in areas north of Naama Bay this week".

The claims that the shark attacks could have been part of a plot by Mossad came from Mohamed Abdel Fadil Shousha, the governor of South Sinai.

"What is being said about the Mossad throwing the deadly shark [in the sea] to hit tourism in Egypt is not out of the question, but it needs time to confirm," he told the state news site, egynews.net.

Others said sharks may have been drawn to shallow waters after cattle being shipped in for last month's Muslim festival of sacrifice, Eid al-Adha, had died and were thrown overboard.

"There is not one reason that will be ignored," said Ahmed el-Edkawi, assistant secretary for the South Sinai region. "We are seeking any reason that causes a change in shark behaviour."

CDWS chairman Hesham Gabr said he had heard nothing about any possible Mossad involvement. He said the likeliest explanations for the attacks were the "irresponsible divers" who fed sharks in the area and ships that had recently dumped a number of sheep in the sea.

The chamber said most diving sites near the resort would be open tomorrow, but not in the area where the attacks had happened. No introductory or training dives would be allowed.

"All snorkel activities and other watersports – with the exception of glass-bottomed boat operations – remain suspended in the whole of the Sharm el-Sheikh coastal area," a CDWS statement said.

The British holiday companies Thomson and First Choice advised holidaymakers in the area to stay out of the water following Foreign Office advice that people should be on their guard.

Local diving experts said single-shark attacks were rare in the area, adding they were mystified as to why so many people had been attacked in such quick succession.

The attacks grabbed the attention of world media and raised fears about the possible damage they could do to Egypt's coastal tourist industry.

"We've seen more attacks in a few days than in the previous 15 years," said Florian Herzberg, dive operations manager at the Reef 2000 centre in Dahab, a resort north of Sharm el-Sheikh.

"It could be a shark with behavioural problems that was deliberately fed different things and now associates humans with food."

Watersports centres said business had dried up after officials banned snorkelling and swimming, leaving tourists with little to do but speculate over the cause of the attacks.

"Egypt is full of rumours and one does not know what to believe," said Gasser Mohamed, a diving instructor at CFun Divers centre in South Sinai. "I see that there are a lot of sharks in the sea and the possible rarity of tuna fish due to overfishing seems to be causing the attacks."