Roadside bombers have killed six American soldiers and an airman, four of them in a single strike northwest of Baghdad. Opposition fighters appeared to be using far more powerful bombs that rip apart armored US vehicles.
An eighth soldier died of a non-combat cause in Baghdad, raising to 25 the number of American soldiers who died this week.
The deadliest attack on Saturday killed four soldiers and wounded an Iraqi interpreter when it blew up their vehicle during combat operations northwest of Baghdad.
Since last Sunday, two roadside bombs killed nine troops in the Baghdad region - five northeast of the capital on Thursday and four in western Baghdad on Wednesday.
Explosions aimed at US troop patrols - usually several heavily armored Humvees or Strykers - killing several troops at once are common, but the recent frequency of such largescale attacks may signal militants are using larger bombs or explosively formed penetrators, known as EFPs, as they fight back against a series of US military operations.
The military has staged a series of counter attacks this week on roadside bomb factories and insurgent strongholds where stockpiles of explosives have been uncovered.
US forces using tips from Iraqi informants raided a safe house before dawn yesterday and detained three militants with suspected of ties to Iran, the military said.The swoop in Sadr City, Baghdad's main Shiite enclave, was the latest in a series of raids on targets where militiamen are believed to have ties to Iran.