Another soldier was killed in Tikrit and several others injured several hours later on Wednesday evening in a resistance attack.
According to the US military, the blast which killed the woman soldier occurred on Wednesday near the entrance to the main United States military base in Saddam Hussein's hometown of Tikrit.
The remote-controlled explosive went off as a convoy of vehicles headed towards the occupying base, US military sources said.
The US Centcom also reported that a 17th Field Artillery Brigade soldier died from a non-hostile gunshot wound at a base camp near Balad on 30 September.
On 29 September one 800th Military Police Brigade soldier and one 82nd Airborne Division soldier died after a military vehicle overturned and became submerged in a canal near Abu Gareb Prison in Baghdad, Centcom said.
Since 1 May when US President George Bush declared combat operations over in Iraq, 82 US occupation soldiers have been killed in resistance attacks.
Earlier on Wednesday, a protest by hundreds of unemployed Iraqis in central Baghdad descended into violence.
One person was injured and two vehicles, including a police car, were set ablaze after the demonstrators protested outside the Vital Enterprises Protection Bureau on Wednesday, Aljazeera's correspondent said.
Job-seekers turned violent when told
there were no jobs
As the protest turned violent and the demonstrators threw stones, Iraqi police officers fired automatic rifles and pistols to break up the crowd. One person was subsequently injured though exact details were not immediately clear.
The protesters had apparently come to a recruitment office for a US-backed local force that provides guards for state property.
But the demonstrators became frustrated after being told week after week there were no jobs available.
The US-installed regime has struggled to revive the moribund Iraqi economy and unemployment is extremely high across the once-thriving country.