Insurgents have abducted the governor of one of Iraq's most dangerous provinces and called for an end to US operations close to the Syrian border.
Raja Nawaf, governor of the western province of Anbar, was seized at a roadblock between the town of Qaim and the provincial capital, Ramadi.
The kidnappers demanded the withdrawal of US troops from Qaim, where the US says it has killed 100 insurgents.
The abduction came after a car bomb attack killed seven people in Baghdad.
In a telephone call to Mr Nawaf's brother, a group claiming to have kidnapped the Anbar governor - who only recently took up his post - said they would hold him captive until US troops pulled back from Qaim.
US military officials say they have killed up to 100 insurgents since it launched Operation Matador in Qaim, 320km (200 miles) west of Baghdad, on Saturday night.
The operation, the largest US offensive in months, was prompted by a string of bomb attacks across Iraq in recent weeks.
The US says its offensive aims to cut off weapons smuggling routes
Marines crossed the Euphrates river on Monday and pushed westwards into the Jazirah desert, a largely unpatrolled area near the Syrian border.
US commanders believe the lawless area is a haven for followers of insurgent leader Abu Musab al-Zarqawi.
Since then they have been fighting house-to-house and say they have encountered stiff resistance.
Fourteen American soldiers have been killed in Iraq since Saturday, at least four of them marines.
Tuesday's car bomb attack hit Saadoun Street, a busy part of Baghdad's business district hit by a similar explosion that killed 17 on Saturday.
The seven who died in the latest blast are thought to be civilians.
Also on Tuesday, a second car bomb explosion wounded six policemen at a police station in the capital.
Meanwhile two US allies, Australia and Japan, are grappling with hostage crises in Iraq.
The fate of Australian hostage Douglas Wood remains unclear after the passing of a deadline set by his captors.
Kidnappers had demanded a withdrawal of Australian troops from Iraq by 1900 GMT on Monday.
Australia has ruled out bowing to the kidnappers' demands, but has promised to try to secure Mr Wood's release.
The 63-year-old engineer has appeared in a video pleading for his life since his capture two weeks ago.
Japan also says its policy on Iraq will not be swayed by kidnappers.
Akihiko Saito, an employee of a British security firm, is missing after his car was ambushed at the weekend.
Islamist group Ansar al-Sunna has claimed to be holding him and released a copy of his ID card as evidence.