Intelligence officials may have uncovered the hideouts of two more key Al Qaeda figures who escaped Afghanistan -- right across the border in Iran.
And one of the men was previously believed dead.
A U.S. official said Wednesday the United States has received reports on the whereabouts of Saif al-Adil, an Egyptian who has been security chief for Al Qaeda leader Usama bin Laden and wanted in the 1998 bombings of two U.S. embassies in Africa; and Abu Hafs the Mauritanian, an operational planner possibly linked to those bombings and the failed plot to blow up unidentified U.S. targets on New Year's Day 2000.
U.S. officials previously said Hafs was killed in January in Afghanistan. New information from foreign intelligence sources and other sources now indicates he survived the war and escaped, said a Pentagon official, who like the other administration official, spoke on condition of anonymity.
Secretary of Defense Donald H. Rumsfeld has said repeatedly that Al Qaeda figures are hiding in Iran, Iraq and dozens of other countries. Suspects have been captured in places ranging from Singapore to Morocco to Yemen to Bosnia.
But this is the first time the location of a possible hideout has been made public before a person was captured.
Speculation on bin Laden's whereabouts continues to focus on the likelihood that he survived the U.S. bombing in Afghanistan and may be hiding somewhere across the border in Pakistan's tribal areas.
Sen. Bob Graham, D-Fla., chairman of the Senate Intelligence Committee, said Wednesday he assumes bin Laden is still alive.
"What I believe is what I have been told by our intelligence agencies, which is that the best analysis is that bin Laden is probably still alive, living in that region between Afghanistan and the tribal territories of Pakistan," he said in a televised interview.
Graham said it would be important to capture or kill bin Laden, but that would not mean the end of Al Qaeda.
"I hope we get bin Laden -- knowing finally that he is either dead or in custody will make us sleep better at night," he said.
The Bush administration called Iran's behavior "unacceptable."
"We call on and urge the Iranian government not to offer terrorists a safe haven," said White House spokesman Scott McClellan, adding that "we want to be clear to the Iranian government on that message."
Because the information was based on intelligence reports, State Department spokesman Richard Boucher would not discuss specifics about the matter.
The men are among some two dozen terrorist suspects on a wanted list kept by the U.S. Central Command, which runs the Afghan campaign. They are part of a still smaller group that the Pentagon fears could rise among figures left in the scattered Al Qaeda network to become key planners in future attacks.
"There are six, eight, ten, twelve people who could pick up that apparatus today, may even have done so today already," Rumsfeld said at a recent press conference. "They know where the bank accounts are, they know who they trained, they know what the training manual says and what these guys are capable of doing. They know where their sources of information are and how to communicate."
U.S. officials said Wednesday that the information on the men's whereabouts had not been confirmed.
In Tehran, Foreign Ministry spokesman Hamid Reza Asefi denied the report, the official Islamic Republic News Agency said.
"Based on its responsibilities, Iran will resolutely fight terrorism, and preventing terrorists from entering Iran's territory is in full conformity with Iran's national interests. It is ugly that some American circles make accusations against Iran without any evidence," Asefi was quoted as saying.
"No member of Al Qaeda is in Iran and Tehran's policy is not to give refuge to this group," Asefi was quoted as saying.
Abu Hafs is a key spiritual counselor in Al Qaeda also known as Mahfouz Ould al-Walid.
Al-Adil, bin Laden's security chief, was thought to be taking over operations following the death of Mohammed Atef, bin Laden's top military commander.
The story on their whereabouts was first reported in Wednesday's editions of The Washington Post. The newspaper cited Arab intelligence sources as saying the pair was planning Al Qaeda operations from Iran.
It's unclear to what degree the government of Iran might be sanctioning the presence of Al Qaeda within its territory. The Bush administration has said Iranian hard-liners who control the military and intelligence services are working with Al Qaeda.
Another Al Qaeda leader named Abu Musab Zarqawi went to Iran after the U.S. war started in Afghanistan, but is believed to have left the country.
Iran says it has arrested 150 people since late March on charges of terrorism and espionage. It isn't clear if the alleged terrorists were members of Al Qaeda or of an opposition group Iranian officials usually refer to as terrorists and counterrevolutionaries.
Earlier this month, the Saudi government also said Iran had expelled 16 Al Qaeda members to Saudi Arabia.