The latest violence came as the US military said Abu Musab al-Zarqawi, who has a $10 million price on his head, is the prime suspect in deadly bombings that hit Najaf and the UN headquarters in Baghdad last year.
The soldier, from the 16th military police brigade, was killed and two were wounded when a device struck an army patrol near Abu Gharib district of Baghdad at about 10:40 pm on Thursday, the military said.
He was was the 258th American soldier killed in Iraq since US President George Bush declared major combat over on 1 May last year.
Earlier the same day, a convoy carrying General John Abizaid, head of US Central Command, and Major General Charles Swannack, commander of the 82nd Airborne Division, was attacked in Falluja.
"Three rocket-propelled grenades were fired at their convoy from the rooftops in the vicinity," US Brigadier General Mark Kimmitt, deputy coalition operations chief told a news conference.
Talks on elections
United Nations experts continued to probe the feasibility of early elections, a day after the world body's top diplomat for Iraq, al-Akhdar al-Ibrahimi, met Shia cleric Ayat Allah Ali al-Sistani, who is demanding an early poll.
Al-Ibrahimi (L) is in Iraq to discuss
the feasibility of early elections
Al-Ibrahimi said although he agreed elections should be held, they had to be well-prepared and held at the appropriate time.
"We are in agreement with Ayat Allah Ali al-Sistani that these elections should be well prepared and should take place in the best possible conditions so that it would bring the results
which he wants, the Iraqi people want and the United
Nations wants," al-Ibrahimi said.
His position appeared to be half-way between those of al-Sistani and the US occupying coalition. The latter argues free and fair elections cannot be held in such a short period, but need preparation.
Al-Ibrahimi heads a nine-member team that arrived on Saturday to gather the views of members of the coalition and the Governing Council, other politicians, religious leaders, lawyers and human rights groups.
In New York, UN Secretary-General Kofi Annan's spokesman, Fred Eckhard, said the UN chief understood there was "a consensus emerging" for direct elections as a result of talks al-Ibrahimi had with a variety of Iraqi leaders.
"There is wide agreement that elections must be carefully prepared, and that they must be organised in technical, security and political conditions that give the best chance of producing a result that reflects the wishes of the Iraqi electorate," Eckhard said.
"Everyone expects elections by 2005," Eckhard said.
"The question is what can be done before 30 June and if it can't be elections what other way can you find to establish a legitimate government," he added.
Diplomats said some transfer of power would take place on 30 June, but that elections could not be held before then.
"They might possibly be able to do it by the end of the year but this is not certain," said one UN envoy.