Story highlights The jihadist group Ansar Jerusalem claims responsibility for the attack

Egyptian official calls the blast a "terrorist attack"

The bus driver was among the four people killed, state TV reports

Bus was carrying 33 tourists from South Korea who had visited a monastery

At least four people died and 14 were wounded Sunday by an explosion on a tourist bus in the Egyptian resort town of Taba, authorities said.

Brig. Gen. Alaa Mahmoud said 33 tourists from South Korea were on the bus and had visited the Greek Orthodox Monastery of St. Catherine's, in the Sinai Peninsula. The bus was headed to Israel and was waiting in line near a border crossing, he said.

According to state-run media, Health Ministry officials said three tourists and the bus driver, who was from Egypt, were killed.

The jihadist group Ansar Jerusalem posted a statement on the radical Islamist website Hanein claiming responsibility for the bombing.

Israeli police dispatched ambulances and patrol cars to the border with Egypt to help if needed, Israeli police spokesman Micky Rosenfeld told CNN.

Egypt's Minister of Tourism Hesham Zaazou said the Egyptian government had taken the "utmost measures" to protect tourists in the country.

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"I'm extremely enraged because of this terrorist attack and this tragic incident," he told CNN by phone as he was traveling to the bombing site.

The Sinai region has seen Islamist militants become more active in recent years.

In January, three soldiers were killed when armed men attacked their bus. And in November, a car bomb killed 10 soldiers.

The Egyptian revolution that toppled strongman President Hosni Mubarak in 2011 brought a resurgence of Islamists, whom his military regime had repressed for decades. This included relatively moderate factions like the Muslim Brotherhood, which swept into power when Mohamed Morsy became president in Egypt's first democratic elections.

But it also included extremists, some who have been inspired by al Qaeda. In the Sinai Peninsula, they have called for the establishment of an Islamist caliphate. The Egyptian military began cracking down on them again.

In July, when the military ousted Morsy in a coup, Islamist extremists in the Sinai saw it as an attack against Islam and stepped up their assaults, particularly against soldiers and military installations.

Sunday's targeting of tourists marks a new threshold in Egyptian terror, at least in recent years.

Taba is in the northeastern Sinai Peninsula, just a few miles from Israel. It was also the scene of a triple bombing in 2004, when 34 people were killed at hotels that were attacked.

The explosion happened so close to the border that a security camera on the Israeli side caught it on tape. Israeli TV network Channel 2, a CNN affiliate, showed the video, which captures the explosion and its initial white smoke on the side of the frame. A piece of debris flies high into the air, then descends slowly to the ground.