A member of the US-led forces in Iraq has been killed in a bomb attack in Baghdad.
The latest violence has hit cities including Karbala
An American spokeswoman said the soldier was killed and another wounded when an explosive device went off on Tuesday morning.
Earlier, the US military said one American soldier was killed and another injured by a homemade bomb in the northern town of Tikrit.
In other violence, at least one Iraqi was reported killed in an explosion on Monday night at a shrine in the holy city of Karbala, south of Baghdad.
Also last night, three mortars hit Baghdad, one landing at a camp of the 2nd Armoured Cavalry Regiment, but the military said no casualties were reported.
Over 130 American soldiers have died in combat since President Bush declared the war over on 1 May.
In Karbala, the blast on a busy street happened close to the gold-domed Imam Hussein shrine - one of the holiest sites in Shia Islam.
There are conflicting reports on the cause of the blast.
Mohammed Abu Jaffar al-Assadi, a Shia cleric who arrived
at the scene minutes after the blast, said a bomb had apparently been planted in a parked car.
But other witnesses said it might have been concealed in a bag left outside a hotel.
The dead and injured apparently were passers-by.
Karbala was rocked last month by clashes between supporters of rival Shia factions. Also in October, gun battles broke out between US troops and backers of a maverick Shia preacher, leaving three American soldiers dead.
Judge reported killed
A senior judge in Najaf has been shot dead, apparently by militants opposed to his involvement in US-backed judicial commission probing former officials in the Saddam Hussein regime, the AFP news agency reports.
Muhan Jabr al-Shuwaili was driven out of the city early on Monday and murdered, according to Najaf's prosecutor general, Aref Aziz, who was also abducted but then released.
Al-Shuwaili had supported the Baath Investigative Commission, set up in August to act on complaints against former Saddam loyalists.