A man believed to be the planner of a series of deadly al-Qaeda attacks in Iraq has been killed, the US says.
Mahir al-Zubaydi, also known as Abu Assad or Abu Rami, was said to head the group behind bombings which killed at least 16 people in Baghdad this week.
US officials described him as the al-Qaeda military commander for the whole of Baghdad east of the Tigris river.
They say he played a key role in planning some of the worst atrocities in Iraq over the past few years.
Zubaydi also took part in the videotaped killing of four Russian diplomats in June 2006, officials say.
US troops targeted Zubaydi on Friday after receiving intelligence following bombings in Baghdad against Shia Muslim mosques.
Troops tracked him down to a house in the Adhamiya district of Baghdad, a strongly Sunni Muslim area, surrounded the building and used loud speakers to order the suspect to surrender, reports the BBC's Hugh Sykes, in Baghdad.
The Americans say he responded by shooting at them, so they shot him, our correspondent says.
A woman reported to be his wife was also killed.
Military officials hailed Zubaydi's killing as a major step in the continuing battle with al-Qaeda militants in Baghdad.
"His removal from the AQI [al-Qaeda Iraq] network will send shockwaves through Baghdad's terrorist bombing networks," a US spokesman told the Associated Press.
The spokesman said the organisation, which has seen a drop in support as Sunni Muslim Awakening Councils have collaborated with the US to curb violence, would now have even greater difficulty recruiting new members.