The Sunni tribal leader cooperating with the United States against al Qaeda in Iraq was killed in an improvised explosive device attack near his house in Anbar Province.
Abdul-Sattar Abu Risha, head of the Anbar Salvation Council (also known as the Anbar Awakening), led the revolt of Sunni tribes who backed the Iraqi government and U.S. forces in Iraq. September 14 marks the council's anniversary.
Abu Risha's brother, Ahmed Abu Risha, has been chosen to lead the Anbar Awakening Council's fight against al-Qaeda in Iraq in the wake of his brother's killing.
Though al Qaeda would have an interest in killing Abu Risha, no group has yet claimed responsibility for his death. The IED blast occurred near Abu Risha's home, targeting his soft-skin SUV. He died instantly, along with his personal security guard and three other guards. Following the attack, a second explosion occurred not far from the first, also intended for Abu Risha's party.
In Iraq, Lt. Gen. Ray Odierno commander of the Multi-National Corps in Iraq hailed the Sunni sheik's leadership.
"The people of Anbar have rejected the kind of violence that took his life. We stand resolved with the people of Anbar and the Government of Iraq to turn back the barbaric ideology that led to tremendous hardships and suffering. This act of murder will serve only to steel that resolve," Odierno said.
The White House National Security Council released a statement "condemning" the tribal leader's killing.
"His efforts, and those of his fellow tribal sheiks, to take the fight to al Qaeda and bring peace and security to Anbar and other regions of Iraq exemplify the courage and determination of the Iraqi people," said White House National Security Council spokesman Kate Starr.
Starr continued: "His death also reminds us that the struggle will require continued perseverance, and the Iraqis are increasingly turning away from al Qaeda as a result of such extreme acts of violence."
Gen. David Petraeus learned of Abu Risha's death during a morning meeting with The Washington Post editorial board and called the Sunni leader's death a "tragic loss."
Petraeus continued, "It's a terrible loss for Anbar Province and all of Iraq. It shows how significant his importance was, and it shows [that] al Qaeda in Iraq remains a very dangerous and barbaric enemy."
Earlier this month the president met with Abu Risha and a group of tribal leaders at the al-Asad Air Base in Iraq.
After the meeting, Bush said, "They were profuse in their praise for America. They had made the decision that they don't want to live under al Qaeda. … They thanked me. I thanked them."
ABC News' Ann Compton, Terry McCarthy and Martha Raddatz contributed to this report.