Usama bin Laden moved to a new hiding place within minutes of the terrorist onslaught in the United States, refusing to tell anyone where he was going or where he had been when the attacks occurred, sources in Pakistan's intelligence service said Thursday.

The sources in neighboring Pakistan spoke on condition of anonymity. Pakistan is one of only three countries that recognize Afghanistan's Taliban government, and is considered to have good intelligence on Islamic militants operating here. A U.S. official, also speaking anonymously, confirmed the Pakistani report.

Bin Laden, a major suspect in Tuesday's attacks on the World Trade Center and the Pentagon, dropped out of sight in August 1998, when the United States fired cruise missiles into eastern Afghanistan following the terrorist bombing of two U.S. embassies in East Africa.

In a statement carried on Taliban radio, Taliban leader Mullah Mohammed Omar accused U.S. investigators of focusing on bin Laden, a wealthy exiled Saudi, "without any proof but because he is so well known."

"Does Usama have planes to train pilots? Where did they get their training? Who trained them? Are they former pilots? From which country? This is the job of a government. In Afghanistan this kind of training is not possible," Omar said.

Bin Laden was last seen in public in February, at his son's wedding in the southern Afghan city of Kandahar.

Kandahar is the Taliban militia's headquarters. Witnesses and other Afghan sources say that near Kandahar's airport is a sprawling housing compound accommodating 300 so-called "Afghan Arabs" — foreign volunteers who came to Afghanistan to fight the Soviet army in the 1980s and ended up in bin Laden's al-Qaeda (The Base) group.

Since Tuesday's terrorist attacks, there have been several reports from Kandahar of Arab nationals moving out of the area, presumably to avoid U.S. retaliation.

In Kabul, the Afghan capital, where Arab nationals have become increasingly visible in recent months, several Arab families have been seen loading their belongings into vehicles and leaving.

Bin Laden is known to travel in small convoys, often in a plain white jeep accompanied by his closest bodyguards and only Arab nationals like himself. Taliban commanders who know bin Laden say he rarely stays in one place for more than two days.

In his travels, Bin Laden is usually accompanied by Ayman Al-Zawari, who was convicted in absentia and sentenced to death for the 1981 assassination of Egypt's President Anwar Sadat.

Bin Laden is known to run training camps in eastern Afghanistan's Paktia, Kunar, Nangarhar and Kandahar provinces, where mountain caves offering limitless hide-outs.

According to Taliban sources, one of Bin Laden's bases is in Paktia province. He shares it with Jalaluddin Haqqani, a former Islamic insurgent who received massive U.S. backing as part of a policy of countering the Soviet invasion.

Built with the help of U.S. money and expertise, the bases are a warren of interlinked caves. Pakistani intelligence officials who used to funnel U.S. money to the insurgents have said they are strong enough to withstand anything short of a nuclear bomb.

Last spring a Taliban security official, who spoke on condition of anonymity, said he had accompanied bin Laden to his hide-outs in the mountains of Kunar province.

The official said five satellite dishes are camouflaged on a mountainside and that while visiting the region he heard conversations by satellite telephone in French and Arabic.

The Taliban leaders condemned Tuesday's attacks, and many Afghan citizens are expressing outrage.

The Taliban foreign minister, Wakil Ahmed Muttawakil, said bin Laden has been denied communications equipment and does not have the facilities to carry out such an assault.

However, the Foreign Ministry was quick to deny rumors that bin Laden was under house arrest, and Muttawakil refused to say where he is. When asked during an interview at a hotel in Kabul three hours after the terrorist attacks, he would only say: "Well, he's not in this hotel."