One Iraqi died and two were wounded when a roadside bomb targeting American troops exploded in Baghdad on Wednesday, said military officials.
There were no further details and no reports of casualties among occupation forces.
Also in the occupied capital, a leader of the Supreme Council for Islamic Revolution in Iraq (SCIRI) was shot dead, reported our correspondent, quoting group sources.
Muhanad al-Hakim, the head of the SCIR in al-Amiriyah quarter of Baghdad, had received death threats a week ago, allegedly from Saddam Hussein loyalists.
Earlier in the day, 12 Iraqis were killed and several wounded when a roadside bomb placed near a fuel truck exploded in Baghdad, according to police.
The huge ball of fire caused by the blast soon engulfed a minibus carrying several passengers.
But US military sources later said the explosion was due to a "traffic accident" and not a bomb.
"Our ordnance experts surveyed the site and found no
evidence of explosives. It was not consistent with a car bomb. It was a fuel truck that simply had a traffic accident," said US military spokesman Captain Jason Beck.
Violence was not confined to the capital. Near the northern Iraqi city of Kirkuk, an unknown number of US soldiers were wounded in the evening when two roadside bombs exploded as their convoy passed, said Iraqi police.
US soldiers dispersed protest with
a show of force
US military spokesmen in the area could not be reached for
Two roadside bombs placed about five metres apart exploded within seconds of each other, said police officials.
One Humvee vehicle was badly damaged and blood stained the road.
Meanwhile, demonstrations against the US capture of Saddam continued for the second day. In the northern city of Mosul student protests were dispersed by US forces with batons and Iraqi police shooting in the air.
Four students were shot during a second consecutive day of demonstrations in support of Saddam, said police.
Demonstrators marched through the streets carrying photographs of the ousted leader who was captured on Saturday.
But shots rang out as they approached a post occupied by the Iraqi Facilities Protection Force and four people were hit, said police officer Bakr Siddiq Muhammad.
Rioting ensued and students attacked the headquarters of a party representing the city's Turkmen minority and set a party car ablaze.
Meanwhile, US troops are scouring a region north of Baghdad for resistance fighters and have raided homes in the town of Samarra, arresting 73 suspects on Tuesday night.
The 4th Infantry Division, based in Tikrit, confirmed the arrests, and said latest searches were part of Operation Ivy Blizzard.
In related news, South Korea's government ended months of divisive debate on Wednesday by announcing its final decision to send a contingent of 3000 troops to Iraq.
A South Korean soldier checks an
Iraqi girl with face burns
The decision endorsed at a cabinet-level security meeting chaired by President Roh Moo-Hyun provides for the deployment of combat and non-combat troops, the president's office said.
However, the contingent will not ensure the security of the region in which it is deployed, said National Security Adviser Ra Jong-yil.
The South Korean contingent will take on responsibility for support of Iraqi peace and rehabilitation, and will independently take charge of a certain region," he said. "The Iraqi military and police will be in charge of security in that region."
The decision must be endorsed by parliament and a motion will be sent to the National Assembly next week, Ra said.
Non combatant assistance
Japan, committed to sending military personnel to Iraq but cautious about their safety, is planning to send its first substantial contingent of 135 ground troops there on 21 February, a national daily said on Wednesday.
Quoting a defence ministry proposal, the Mainichi Shimbun said Japan would first send an advance party of 28 troops on 14 January to begin preparations, followed by a 78-strong logistics team on 31 January.
The 135 troops will then leave, and a total of about 550 troops will be in place by the end of March, according to a ministry proposal which the paper said had been presented to the ruling coalition.