A roadside bomb has killed an important Sunni tribal leader who was cooperating with U.S. troops fighting al-Qaida insurgents in Iraq. Sheikh Abdul Sattar Abu Risha and two bodyguards died in the attack near his home in Ramadi, the capital of al-Anbar province. VOA correspondent Meredith Buel has details from the Pentagon.

Abu Risha was the leader of the Anbar Salvation Council, also known as Anbar Awakening, an alliance of Sunni clans backing the Iraqi government and U.S. forces to push al-Qaida fighters out of western Iraq.

President Bush met Abu Risha and other tribal leaders during a highly symbolic trip to Anbar province on September 3.

Last year, the Sunni sheikhs switched their allegiance from al-Qaida to the Shi'ite-led government in Baghdad.

Mr. Bush said he was pleased with the progress in Anbar, which has gone from one of the most violent, anti-U.S. areas in Iraq to a security success story.

Pentagon spokesman Bryan Whitman told reporters that Abu Risha's death is a major loss.

"It is a most unfortunate and tragic loss," said Whitman. "It demonstrates the lengths that the enemies of Iraq will go to to divide Iraq and to deny all Iraqis a better, brighter, more prosperous and peaceful future."

Al-Qaida once controlled large areas of Anbar, but the terrorist network angered local tribal leaders with its indiscriminate killing of civilians and harsh interpretation of Islam.

Abu Risha was part of a group of young sheikhs whose power grew after their elders fled Anbar following the assassination of senior sheikhs by al-Qaida insurgents.

He was instrumental in getting young men to join local police forces, a development that has sharply reduced violence and forced many al-Qaida fighters to flee to other parts of Iraq.

A charismatic figure, Abu Risha lived within the walls of a massive compound that houses several villas, his extended family, camels and palm trees. The compound is guarded by a tank and sits across the street from the largest American military base in Ramadi.

Pentagon spokesman Bryan Whitman says his death is a reminder of the continuing resolve needed in Iraq.

"It serves to remind us that the struggle will require continued perseverance of the Iraqi people and the leadership and wisdom of men with the character and vision of the likes of Sheikh Abdul Sattar," said Whitman.

The U.S. military commander in Iraq, General David Petraeus, highlighted what he called dramatic security gains in Anbar during testimony to the U.S. Congress this week.

Brian Katulis, a senior fellow at the Center for American Progress, says Abu Risha's death will raise questions about U.S. efforts in Anbar.

"Well I think it is really important because the Bush administration has been trying to make an argument that what they are doing is fostering bottom-up reconciliation and the center of that is in al-Anbar," said Katulis.

"Here is a major figure who was killed in an attack, we don't know who has done it, but it raises some serious questions of whether there is truly reconciliation and really sustainable security and stability being created by these efforts on the part of the Bush administration," he added.

General Petraeus called the killing of Abu Risha a terrible loss for Anbar province and all of Iraq.

He says the attack shows al-Qaida in Iraq remains a very dangerous and barbaric enemy.