WASHINGTON -- Despite their fall from power, a half-dozen key Taliban leaders pose a threat to U.S. interests in Afghanistan and elsewhere and remain high on America's target list.

Mullah Mohammed Omar, the Taliban supreme leader, heads the list. He vanished from Kandahar as U.S.-backed forces rolled in.

In February, he was believed to be in the mountains of central Afghanistan, near the town of Bagram. He is not thought to be with Osama bin Laden, the al-Qaida leader whose location remains a mystery. A top Omar aide, Tayeb Agha, is also wanted by U.S. forces.

Regrouping al-Qaida

Another key figure who has survived is Jalaluddin Haqqani, a former U.S. ally and the Taliban's former minister of frontier affairs. Since the war in Afghanistan, he has been supporting efforts by al-Qaida and Taliban fighters intent on regrouping, U.S. officials say.

The officials believe Haqqani was working closely with al-Qaida field commander Abu Zubaydah, who was said to have been driving the terrorist network's efforts to reconstitute itself from Pakistan, with an eye toward conducting new international terrorist attacks. Abu Zubaydah was captured March 28, but Haqqani was not found.

Afghan and U.S. authorities say Haqqani, too, was directing from afar the regrouping of al-Qaida and Taliban forces in Paktia province in Afghanistan that led to the Americans' late-winter offensive, Operation Anaconda. The Taliban ground commander in the region, Saif Rahman Mansour, also escaped.

Before the war, Haqqani ruled much of Paktia province and consented to bin Laden's construction of training camps there.

Haqqani was a U.S. ally during the Afghan war against the Soviet Union in the 1980s, receiving money and weapons from the CIA through Pakistani intermediaries, according to former U.S. officials with experience in the region. He tormented the Soviets in the region, becoming one of the most successful Afghan mujahedeen commanders. He remained a regional power, then sided with the Taliban when that group rose to prominence in the mid-1990s.

An ethnic Pashtun, he has family in Pakistan and visited that country during the U.S. war in Afghanistan, but it's unclear where he is now.

Military officials said capturing Taliban leaders remains a priority since they command enough followers to threaten American interests.

"Our mission there still remains to capture al-Qaida and Taliban members, and that would especially include any of the leadership of those organizations," said Marine Corps Gunnery Sgt. Charles Portman, a spokesman for U.S. Central Command.