TABA, Egypt — Dozens of Bedouin tribesmen have been detained on suspicion they supplied the explosives for coordinated car bombings at two Egyptian resorts that killed at least 33 people, most of them Israelis, officials said Saturday.

Israel's counter-terrorism chief urged Israeli tourists in Egypt to return home immediately, saying they were in danger.

At the Taba Hilton, scene of the deadliest blast, investigators searched for clues to the identities of the attackers. Israeli officials have said they believed the al-Qaida terror network was most likely behind the attack, while Egyptian officials said it was too early to point to suspects.

Fingerprints were lifted from the car bomb, which consisted of 440 pounds of explosives, and DNA samples were taken from body parts found nearby to determine whether suicide bombers drove the vehicle.

Three car bombs exploded Thursday night, one at the Taba Hilton just south of the Egypt-Israel border and two at a bungalow beach camp further south along the Red Sea coast.

Egyptian and Israeli rescuers used jackhammers, dogs and their bare hands to search the blood-stained hotel wreckage on Saturday. Trees around the hotel were filled with the bodies of charred birds.

Three bodies, including that of a toddler, were pulled from the rubble, bringing the death toll to 33, the Israeli military said. More than 100 people were injured, including two people who work at the American embassy in Israel.

Dan Arditi, head of Israel's counter-terrorism agency, said Saturday that Israeli tourists in the Sinai Peninsula are still in danger, and urged them to come home immediately. Thursday's attacks "don't lessen, even in the slightest, the risk that this will happen again," he told Israel Radio.

A month ago the agency urged Israelis to stay out of Sinai, saying it had concrete warnings about plans for a terror attack.

Israel's government had never before issued such a severe travel advisory, but thousands of Israelis ignored it and spent the Jewish holiday period, which began in mid-September, in Sinai resorts. Many Israelis considered the desert peninsula a safe place to get away from their country, which has been hit by scores of Palestinian suicide bombings in the past four years of fighting.

After Thursday's attacks, thousands of frightened Israeli tourists returned home, but others remained.

"I recommend that Israeli citizens who are still in the Sinai come back, as quickly as possible," Arditi said Saturday, suggesting that it is possible the attackers his agency had warned about were not those who carried out Thursday's bombings.

Israeli security sources said September's warning apparently referred to Palestinian militants trying to sneak out of Gaza, which borders on the Sinai. The peninsula is the main weapons smuggling route for Palestinian militants.

A U.S. counterterrorism official in Washington said American officials suspect Osama bin Laden's network played a role because the bombings show a level of sophistication that fits al-Qaida's usual operational style, the official said. The official, speaking on condition of anonymity, also said Palestinian or Egyptian militant groups should not be ruled out.

Egyptian security officials said they have arrested dozens of Bedouin tribesmen on suspicion they supplied the explosives for the attacks.

President Bush offered to help Egypt track down those responsible.

"By targeting Muslims and Jews, Egyptians and Israelis, and women and children, the terrorists have shown their total contempt for all human life and for all human values," he said.

There were several claims of responsibility — including one from an al-Qaida-linked group — but none appeared credible.

The Taba Hilton was at 95 percent capacity with up to 900 guests and 500 employees inside when a car crashed into the lobby. The front of a 10-story wing of the hotel came crashing into the lobby. A hotel worker sleeping on the third floor was blown nine feet in the air and killed.

Parents searched frantically for their children, and rescue worker Gefan Naty said a mother and daughter fell from the seventh floor. The daughter survived, she said. The mother did not.

Within two hours, two more car bombs detonated nearly simultaneously outside the backpacker-oriented beach huts of Ras Shitan, 35 miles to the south, where many Israeli youths were spending the holiday.

South Sinai Gov. Mustafa Afifi said an Egyptian security guard was suspicious about one of the cars and intervened, preventing it from blowing up close to lodging.Had Latham won, he would have become one of the country's youngest leaders.