CAIRO — An explosion tore through a bus filled with South Korean sightseers in the Sinai Peninsula on Sunday, killing at least four people and raising fears that Islamic militants have renewed a bloody campaign to wreck Egypt's tourism industry.
The bombing near the tip of the Red Sea's Gulf of Aqaba was the first attack against tourists in Sinai in nearly a decade.
There was no claim of responsibility. But the blast bore the hallmarks of attacks blamed on al-Qaida-linked militant groups that have been battling government forces in Sinai's restive north for years.
At least three South Korean tourists were killed and 12 seriously wounded, according to Egyptian security officials. The Egyptian bus driver was also among the dead, the officials said.
"I am deeply saddened by the incident," Tourism Minister Hesham Zazou told state TV. The Egypt's interim president called the attack a "despicable act of cowardice" and vowed to bring the culprits to justice.
Egypt's vital tourism sector, which normally accounts for about 11 percent of the economy and 20 percent of all foreign currency revenue, has been badly hit by the deadly turmoil that has roiled the country since the 2011 revolt that overthrew ruler Hosni Mubarak.
Sunday's blast came as signs of a slow recovery in the industry were emerging, especially at Red Sea resorts in Sinai like Sharm el-Sheik.
"The sad consequence for Egypt is that this takes the tourism industry and devastates it for years into the future," said Jon Alterman, director of the Middle East Program at the Center for Strategic and International Studies in Washington.
Egyptian security officials said they believe the blast was caused by either a car bomb or a roadside bomb that was detonated by remote control.
Rescue workers found the remains of four and perhaps five people, according to Khaled Abu Hashem, the head of ambulance services in southern Sinai.
In Seoul, the Foreign Ministry said in a text message that 31 passengers from a church in Jincheon were being led by a South Korean tour guide. Two of its citizens were killed and nine wounded, the ministry added.
The discrepancy in the death toll could not be reconciled.
The attack stoked fears that a deadly campaign against tourists similar to one waged in the 1990s by extremists may have resumed. In 1997, gunmen opened fire at the Temple of Hatshepsut in the city of Luxor, killing 58 tourists and four Egyptians.
Sunday's bombing was the first attack against tourists in Sinai's southern region since a spasm of bloodshed in 2004-06 that killed about 120 people. That included a bombing at a luxury hotel in Taba in 2004 that left 34 people dead, 11 of them Israelis.
The bus in Sunday's attack had set out on a journey from Cairo and was about to enter Israel from the border town of Taba, officials said. Security officials said it arrived at Taba from the ancient Greek Orthodox monastery of St. Catherine's in Sinai.
The officials spoke to the Associated Press on condition of anonymity because they were not authorized to speak to the media.
Since the military ouster of Egypt's last elected president, Mohammed Morsi, in July, jihadists operating mostly in the northern Sinai have carried out hundreds of bombings, assassinations and at least one attack using a rocket-propelled grenade. The victims have included soldiers, police officers and Christian residents.
In recent months, the attacks have spread beyond Sinai to other cities as well as the heart of the capital. At least six people were killed in Cairo last month when bombs scattered around the city exploded outside a security headquarters and other buildings. A Sinai-based militant group, Ansar Beit al-Maqdis, or the Champions of Jerusalem, has claimed responsibility for several of the deadliest attacks, including the downing of a military helicopter late last month.
Information from the New York Times was used in this report.