Interior Minister Prince Nayef said the bombers did appear to share al Qaeda's beliefs, CBS News Correspondent Tom Fenton reports. While it was uncertain if they were actually affiliated with the terrorist network, "all indications point to that," Nayef said.
In a direct message to Americans and other foreign workers, Nayef made it clear he could not guarantee there wouldn't be further suicide attacks. He warned Westerners not to expect stricter security than that enjoyed by ordinary Saudis.
Meanwhile, Prince Bandar bin Sultan, the Saudi Ambassador to the United States, was called home on a mission related to terrorism, a Saudi adviser told Fox. No details on the mission were disclosed.
Prince Bandar is known for handling some of his country's most delicate diplomatic tasks and for his close relations with the U.S. administration.
Of the five dead suicide bombers, three have been identified as members of a 19-person group that the Saudi Security Services failed to arrest during a shoot-out at a terrorist safe house days before the coordinated bomb attacks last week that left 34 people dead, including eight Americans.
Up to sixty FBI and other American security experts are now searching the debris for clues.
But while Nayef says an international effort is needed to crack down on terrorism, he downplayed the role being played by U.S. investigators. Nayef said they had come to examine "the sites and we welcomed them based on that, for examining only."
Nayef's comments on the U.S. role could have been an attempt to answer any domestic criticism his government is ceding control to the Americans.
The Saudi government is wedged between domestic critics who are nervous about such cooperating, and American skeptics who question the kingdom's commitment to battling terrorism.
Reflecting the competing pressures, Nayef's remarks contrasted with interviews Adel al-Jubeir, a Saudi foreign policy adviser, gave on Sunday morning talk shows in the United States.
The Americans are "helping us with the investigation," al-Jubeir told Fox News. "They're providing support to us. They're sharing whatever information they have. They're sharing their expertise."
In a report that could frustrate the Saudis efforts to repair their country's reputation, The Washington Post says some of the guns seized in the raid on the safe house have been traced back to the Saudi national guard.
Officials tell The Post some members of the Saudi national guard have been involved in illegal gun sales for years, but say officers were likely motivated by money more than ideology.
They also say there's no indication that al Qaeda has infiltrated the force that is supposed to protect the Saudi government.
U.S. officials have said Americans would be helping, not running, the investigation into the bombings.
"We're getting real and good cooperation. They're being totally cooperative," a U.S. official in Riyadh said Monday of the Saudis working with the FBI.
He said reports that Saudi authorities were obstructing the investigation were "100 percent false."
U.S. officials complained about being denied access to evidence, witnesses and suspects after the 1996 truck bombing of the Khobar Towers dormitory that killed 19 U.S. military personnel. This time, both sides have said they expect better cooperation.
The U.S. official said the FBI was not interrogating any of the suspects, adding that he thought it was useful that Saudi authorities were handling the interrogation of Saudis detained in connection with the blasts.
He said that there weren't "tens of thousands of active al Qaeda members" in the kingdom, but "we believe the al Qaeda presence here is more than a single cell or two."