Israeli officials say they suspect al-Qaeda involvement in bomb blasts at Egyptian resorts popular with Israelis, in which at least 28 people died.
Dozens were injured in the bomb attacks
The biggest of the three attacks, at the Hilton hotel in Taba, on Egypt's border with Israel, killed 26 people.
The others hit a backpacker camping area near the resort of Nuweiba, 60km (38 miles) further south, killing two.
Rescuers are searching the rubble of the Hilton hotel, but say there is little hope of finding more survivors.
Israeli officials said the Taba attack was caused by a car bomb, which exploded after the vehicle rammed the hotel, and a suicide bomber who detonated a separate bomb.
More than 100 people are reported to have been injured.
The other two bombings on Thursday evening were in a campsite at Ras al-Shitan, an area that is popular with young Israeli backpackers.
The dead are believed to be mainly Israeli, as well as at least five Egyptians and one Russian.
Israeli Deputy Defence Minister Zeev Boim, who is in Taba, said it was too early to say who carried out the attacks, which could not have been anticipated.
But he told reporters: "In my personal opinion, it seems that it is more fitted to the international terror groups like al-Qaeda, or some branches of al-Qaeda."
The Palestinian militant groups Hamas and Islamic Jihad have denied they were
Dozens of Israeli emergency workers are hunting through the rubble of Taba's Hilton hotel, says the BBC's James Reynolds at the site.
As dusk fell, they set up floodlights to continue their search.
"We are still searching for life. We are digging almost by
hand," Israeli Major-General Yair Naveh said.
About 30 people are still unaccounted for, including two Italians.
Eleven floors on one side of the hotel, including the ceiling of the dining room where
tables were set for dinner, collapsed after the blast.
The devastation is astonishing, our correspondent says.
Palm trees have been felled, spiral staircases are lying on their sides and everywhere is blackened, he reports.
Thousands of Israeli tourists have been flooding back into Israel.
Israeli Prime Minister Ariel Sharon and Egyptian President Hosni Mubarak have agreed in the aftermath of the blasts to reinforce co-operation to fight terrorism together.
RECENT ATTACKS ON ISRAELI/JEWISH TARGETS OUTSIDE ISRAEL
1985: Palestinian militants attack El-Al counters at Rome and Vienna airports simultaneously, killing 19
1986: Gunmen kill 22 worshippers in a raid on an Istanbul synagogue
1992: Car bomb attack on Israeli embassy in Buenos Aires kills 29 people
1994: At least 96 people are killed in the bombing of a Jewish community centre in Buenos Aires
2002: Bombing of Israeli-owned hotel near the Kenyan resort of Mombasa kills 16 people
2003: Car bombs explode outside two synagogues in Istanbul killing 25 people
It is the first major attack on Egyptian soil since the mass killing in the city of Luxor in 1997, in which 58 tourists were shot or hacked to death by Islamist militants.
Egypt's Tourism Minister, Ahmed al-Mahgrebi, said the bombings were different from previous attacks targeting the tourism industry.
His desire to emphasise the difference is clearly aimed at preventing a collapse of the industry like that which followed the Luxor killings, the BBC's Heba Saleh reports from Cairo.
Security on the Sinai coast has remained relatively lax because Israelis see this zone as an extension of their homeland.
Taba is the main crossing point between Israel and Egypt, and a major gateway for thousands of Israelis going on holiday to resorts and hotels on the Red Sea.
Last month, the Israeli government urged its citizens not to visit the country, saying there had been a firm threat to tourists there.
Israel has now told its citizens to leave Egypt, and the US and Germany have warned their citizens against travelling in the Sinai peninsula.
The bombings are the first major attack on Israelis abroad since the bombing two years ago of a hotel near the Kenyan resort of Mombasa, in which some 16 people died.