Troops were attacked twice on Monday in the predominantly Sunni Muslim city of Baqouba, 35 miles northeast of Baghdad, said Maj. Neal O'Brien of the 1st Infantry Division.
In the first attack, one soldier was wounded by an improvised explosive device — a homemade bomb. In the second attack, two soldiers were wounded by small arms fire and evacuated to the 31st Combat Support Hospital in Baghdad, O'Brien said. All three are in stable condition.
Also Monday, a mortar attack in north-central Baghdad killed a U.S. soldier and wounded six other soldiers, the military said. A contract worker was also wounded.
Iraqi insurgents also gunned down four U.S. Marines on Monday west of Baghdad, apparently stripping the dead of their flak jackets before fleeing.
In other developments:
A videotape delivered to Associated Press Television News showed the bodies of the four Marines lying in what appeared to be a walled compound. They were in uniform and one was slumped in the corner of a wall.
The bodies had no flak vests — mandatory for U.S. troops in contested areas — and at least one was missing a boot. Next to one body is an open fieldpack, suggesting the dead were looted.
Brig. Gen. Mark Kimmitt, coalition deputy operations chief, confirmed the killings but gave few details. He said a U.S. quick reaction force found the bodies after the troops failed to report to their headquarters as required.
The mortar attack happened in north-central Baghdad. Seven Army soldiers were wounded in addition to the one killed, the U.S. command said.
Hundreds of South Koreans attended a candlelight vigil in Seoul Monday to protest the government's decision to send 3,000 troops to Iraq, the third-largest contingent after the United States and Britain. South Korea now has 600 military medics and engineers in the southern city of Nasiriyah.
The hostage Kim, 33, who works for a trading company in Baghdad, was believed to have been kidnapped about 10 days ago. A videotape broadcast by the Arab television station Al-Jazeera shows him pleading for his life.
The kidnappers claimed to be from the Monotheism and Jihad group led by Jordanian-born terrorist Abu Musab al-Zarqawi, who is believed to have ties to al Qaeda.
Chanting anti-U.S. slogans, hundreds rallied in Fallujah on Monday to protest an American airstrike on Saturday. Demonstrators accused the Americans of falsely claiming that al-Zarqawi had sought refuge in Fallujah to create an excuse to attack the city.
Kimmitt told reporters the attack killed "key personnel in the Zarqawi network" but he would not confirm that any foreign fighters were among the dead.
Iraqi officials in Fallujah, long one of the centers of anti-American militancy, maintain the attack killed only Iraqi civilians. The Iraqi Health Ministry said at least 17 people died.
The recent kidnappings and attacks appear aimed at undermining the interim Iraqi government set to take power June 30, when the U.S.-led occupation formally ends. U.S. and Iraqi officials have vowed to go ahead with the transfer.
Coalition spokesman Dan Senor said that by week's end, all Iraqi government ministries would be under full Iraqi control.
Interim Prime Minister Iyad Allawi has promised to crush the terrorist threat and said Sunday his administration was considering martial law in some areas to restore law and order.
But both he and the interim president later sought to temper those remarks, saying martial law was only one of several steps under consideration.
In an interview Tuesday with the British Broadcasting Corp., Allawi said his Cabinet was considering "public safety laws" rather than martial law as it devised a security strategy for Iraq.
Iraqi President Ghazi al-Yawer said Monday the government would be within its rights to impose martial law, but it was not inevitable.