Three American soldiers were wounded on Wednesday in a bomb attack on a military vehicle in the town of Habbaniyah, west of Baghdad.
In a separate incident another two soldiers were injured in the Iraqi capital when a bomb exploded.
The attacks on the soldiers came as US military commanders admitted they expected more American soldiers to be targeted in the Iraqi capital, Baghdad.
General Ricardo Sanchez blamed the attacks on ''terrorists'', adding that those attacking US soldiers were becoming more desperate and determined to inflict injury on troops.
''We expect them to get more radical and desperate as they continue to lose forces,'' he said.
The general went on to claim that al-Qaida was operating in Iraq along with the group Ansar al-Islam.
''They are demonstrating local co-ordination and synchronisation, and at regional level we have seen that co-ordination,'' he said.
The violence in Iraq continued on the eve of an international conference in Madrid, aiming to secure $36 billion by 2006 to assist in the re-construction of the war torn country.
''I think that it would be a sad thing if the French government could not find a way to participate in the reconstruction of Iraq''
head of the US-led occupation authority
President Bush has called on countries around the world to come forward and donate money to help stabilise the country.
Paul Bremer, the head of the US-led occupation authority, said that he expected France to come to the conference with a view to investing in Iraq.
''I think that it would be a sad thing if the French government could not find a way to participate in the reconstruction of Iraq,'' he said.
Meanwhile, in the town of Falluja, west of Baghdad, about 100 religious leaders staged a protest to demand the release of a leading imam, Shaikh Jamal Shakir Nidal, arrested by occupation forces earlier this month.
Crowds chanted "Death to America" and held up anti-US banners.
In a separate incident, Iraqi police in northern Baghdad announced the arrest of a man that they say is responsible for a string of attacks against occupation soldiers.
Iraqi police named him as Ali Muhammad Ali, 35, who allegedly confessed to launching attacks against US troops and Iraqi police.