At least 88 people have been killed in bomb attacks in the Egyptian resort of Sharm al-Sheikh, hospital staff say.
The attacks happened at the height of the tourist season
Some 200 more were injured in the overnight blasts. The first, in the Old Market, was followed by two more in Naama Bay, where a hotel was badly hit.
Egyptian President Hosni Mubarak vowed to continue the "battle with terrorism" as he visited the sites of the attacks, the worst in Egypt's recent history.
Most of the dead are Egyptians, but foreigners are among the victims too.
A 34-year-old Italian man on his honeymoon and a Czech citizen have been confirmed dead, and at least 20 of those injured are thought to be foreign.
The blasts come less than a year after 34 people died in an attack further north in the Sinai Peninsula.
Egyptian Interior Minister Habib al-Adli condemned what he called an "ugly act of terrorism" and said police were following leads.
"We have some clues, especially about the car that was exploded in the Old Market, and investigators are pursuing," Associated Press news agency quoted him as saying.
US Secretary of State Condoleezza Rice, on a visit to neighbouring Israel, denounced "the horrific terrorist bombings". She vowed that Egypt and the US would "confront and defeat this scourge that knows no boundary and respects no creed".
The blasts came within minutes of each other, shortly after 0100 local time (2200 GMT), when the bars and markets were busy.
In the most devastating attack, a bomber rammed his car into Ghazala Gardens Hotel, according to an eyewitness.
"A suicide car bomber forced the barrier at the entrance of the hotel. A member of the security staff tried to stop him but he sped towards the reception and there was a huge explosion," an unnamed hotel employee told AFP news agency.
Parts of the front walls of the hotel collapsed, trapping people under the rubble.
A few hundred metres away, a bomb went off in a car park near the Moevenpick Hotel and popular nightlife spots, causing widespread damage and casualties.
In the Old Market area blast, about 4km (2.5 miles) away, 17 people - believed to be Egyptian workers - were killed as they gathered at a street cafe, rescue officials said.
"This flaming mass flew over my head, faster than a torpedo and plunged into the water," Mursi Gaber, who was working on a nearby beach when the blast happened, told AP.
"There were body parts all over the steps down to the beach."
Sabina Salvatore, an Italian diving instructor, was on a boat at the time of the blasts.
"Suddenly we looked at Old Sharm and we saw this fire coming up and after this fire some sounds... an explosion and then more fire and everything was shaking," she told the BBC News website.
"After this bomb, silence, then a lot of people screaming."
Witnesses said there was pandemonium as dazed and shocked tourists fled to safety.
"We went outside on to the street where we were met with hundreds of people running and screaming in all directions," British tourist, Fabio Basone, told the BBC.
British policeman Charlie Ives was in a cafe about 50 metres (160ft) away from where two explosions went off.
"The whole area was quickly covered in debris. There was a huge ball of smoke that mushroomed up. It was mass hysteria," he told the BBC. Speaking after touring the bomb sites, President Mubarak said the "cowardly, criminal act" would "only increase our determination in chasing terrorism, cornering it and uprooting it".
"Our battle with terrorism will continue with all the strength, resolve and will that we have," he added.
In a statement posted on an Islamic website, a group calling itself the Abdullah Azzam Brigades, al-Qaeda, in Syria and Egypt, said it carried out the bombings, the AP news agency reported, although the claim has not been verified.
The bombings happened at the height of the summer tourist season in Sharm al-Sheikh, and coincided with an extended holiday weekend to mark the anniversary of the 1952 Egyptian revolution.
It was the first such attack since last October, when 34 people died in car and truck bomb attacks at Red Sea resorts on the eastern coast of the Sinai Peninsula.
The previous worst attack in Egypt occurred in 1997, when Islamic militants killed 58 foreign tourists and four Egyptians near the southern city of Luxor.
Tourism is Egypt's most lucrative industry, worth about $6.6bn a year.