Out of Desert Poverty, a Caldron of Rage in the Sinai

"We now feel like the Egyptian government is an occupation government," said Emad Bullock, 43, an engineer and carpet merchant. "It is hard to look at this and accept it as our national government."

Like the rest of the Middle East, this area has been buffeted by a huge population of young people with no work and by anger over the Iraq war. El Arish is just 30 miles from the border with the Gaza Strip, and its youth, once isolated, see the world via satellite television and the Internet.

Local community leaders said they are most worried about the unemployment. One local study concluded that just 8 percent of those age 20 to 30 have full-time jobs, and that 92 percent depend on seasonal work, like farming, which can pay as little as $2 a day.

"The most important thing is our living standards," said Reda Saleh, a Palestinian whose brother, Ayad Said, was a suicide bomber in an attack in Taba in 2004. "Why would he want to die if he had a decent life? Why would he go and do this if he had a decent life?

"This life," said Mr. Saleh, a 20-year-old illiterate mechanic, "isn’t worth living."

The animosity in El Arish is so deep that some people here say they admire the bombers. Some say they are resisting the government, others see them as bringing the misery of Bedouin lives home to foreigners who come on carefree vacations.

"Because of the security pressure here people feel proud," said Khalid Arafat, a local tribal leader. "They think most of those killed were Jews and foreigners."

It remains impossible to say what ultimately drove the sons of this coastal city toward terrorism. Friends of Mr. Melahy said that while he was growing up he was observant but not fanatical. He listened to music, a sign that he was not extremist, and went off to law school in Zagazig in the Nile Delta.

But when he returned, he had grown a long beard. He started yelling at his friends, telling them not to smoke or listen to music, and he gave up law, because he said the only law was God’s law. Instead of opening a legal practice, he started working as a farmer, struggling to grow tomatoes and cantaloupe in a patch of sand with salty well water.

The police now say that is when he and a group of other local young men began to form their terrorist cell. The cell, Tawhid and Jihad, was heavily influenced by men like Osama bin Laden, Abu Musab al-Zarqawi and by Wahhabism, an austere sect of radical Islam whose roots lie in the Arabian Peninsula.

Besides the attack in Dahab last month, the authorities contend the group is also responsible for the suicide attacks on Taba in 2004, Sharm el-Sheik in 2005, and three separate bomb attacks on multinational peacekeeping forces at the border with Israel.

"I don’t like the way he was religious," said Osman Abu Khoaiter, who said he and Mr. Melahy were friends before Mr. Melahy became "committed." "It was too much. Most of his friends went to die in Gaza or are now hiding in the mountains."