A bomb tore through a bus carrying South Korean sightseers near an Egyptian border crossing with Israel on Sunday, killing three tourists and the Egyptian driver, a senior official said.
It was the first attack on tourists since the ouster of Islamist president Mohamed Morsi by the army in July sparked civil unrest and a spate of attacks across the country that have mainly targeted security forces.
The bomb exploded in the front part of the bus at the Taba border crossing with Israel in south Sinai, the interior ministry said.
South Sinai governor Khaled Fouda told AFP three of the dead were South Koreans, along with the Egyptian driver.
The South Korean foreign ministry confirmed the death of two of its nationals, saying they were members of a Christian church on tour.
A doctor who had been waiting for a bus nearby witnessed the blast.
"There were body parts and corpses. I saw the corpse of a man who appeared to be Korean, with a leg missing," said Ahmed Ali, who runs a clinic in a neighbouring resort.
A health ministry spokesman said 15 were wounded in the attack, and were in stable condition in hospital.
The explosion blew off the front of the yellow bus and tore out parts of the roof.
The interior ministry said the tourists had set off from Cairo and were waiting at the crossing to enter Israel when the explosion happened.
The attack is likely to further damage Egypt's tourism industry, a once vital source of revenue that has suffered during the three years of unrest following the uprising that toppled president Hosni Mubarak.
"Terrorism has no religion. The police and the army are working to eliminate it," Fouda said.
A spokesman for the Israel Airports Authority, which is responsible for border security, told AFP that the Taba crossing had been closed in the wake of the blast.
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No one immediately claimed responsibility for the attack.
- Tourism hit hard -
Scores of Egyptian policemen and soldiers have been killed in bombings in Sinai and the Nile Delta, but Sunday's attack was the first to target tourists since Morsi's overthrow.
The unrest since last summer, including regular demonstrations by Morsi supporters that have set off deadly clashes with police and opponents, has severely hit tourism, which has been targeted sporadically by militants over the past two decades.
The government's census agency said the number of tourists was down in December 2013 by almost 31 percent compared with the same month in 2012.
Sunday's bombing came as a court in Cairo began trying Morsi and 35 co-defendants on charges of espionage and collusion with militants to launch attacks in Egypt.
The military-installed government has accused Morsi's Muslim Brotherhood of masterminding the attacks that have also targeted police headquarters in Cairo.
The Brotherhood, now designated as a terrorist group, publicly renounced violence decades ago and denies involvement in the bombings.
The deadliest attacks have been claimed by the Sinai-based Ansar Beit al-Maqdis group, whose leadership is drawn from militant Bedouin who want an Islamist state in the peninsula.
That group also took responsibility for downing a military helicopter in Sinai on January 25 using a heat-seeking shoulder-fired missile.
The attack prompted concerns that militants could use such weapons to target commercial flights to resorts in south Sinai.
Between 2004 and 2006, scores of Egyptians and foreign tourists were killed in a spate of bombings in resorts in south Sinai.
In 1997, Islamist militants massacred dozens of tourists in a pharaonic temple in the southern city of Luxor.
In Cairo in 2009, a French tourist was killed in a bombing at the historic Khan al-Khalil bazaar, which police at the time blamed on militants from the neighbouring Palestinian Gaza Strip.