This week features key dates in recent Iraqi history
American Defence Secretary Donald Rumsfeld has warned that attacks on troops in Iraq may increase even further this month.
Mr Rumsfeld said attacks might be timed to coincide with a string of important anniversaries for the ousted regime this week.
One US soldier was killed and six injured in an ambush on their convoy in Baghdad on Monday.
The attack came hours before a new, all-Iraqi Governing Council appointed by the occupation forces was due to begin work in the city.
Mr Rumsfeld was speaking at the start of a week of Saddam-era anniversaries:
About 2,000 Iraqi Communists held a rally on Monday to mark the coup anniversary - one of the few holidays not to have been scrapped by the new Governing Council.
"I'm afraid we're going to have to expect this to go on," said Mr Rumsfeld on Sunday, referring to hit-and-run attacks which have left an estimated 31 US troops dead and scores wounded since the end of major combat on 1 May.
"There's even speculation that during the month of July, which is an anniversary for a lot of Baathist events, we could see an increase in the number of attacks."
Barely a day passes without a new hit-and-run attack
There was, he added, debate in the administration over how organised resistance was but he again acknowledged that the fact that Saddam Hussein had still not been found was a problem.
He also conceded that the number of US troops in Iraq might have to stay at around 150,000 for the foreseeable future and might even have to increase.
US forces are carrying out a security drive codenamed Operation Ivy Serpent to forestall attacks during the anniversary week.
In other developments:
About 300 former Iraqi soldiers gathered at Baghdad airport to protest at being unpaid for four months
India rejected a US request for peacekeeping troops for Iraq, saying it required an explicit UN mandate for any deployment
- General John Abizaid, the new head of US Central Command, is due to visit Turkey shortly after the brief detention of 11 Turkish soldiers by US troops strained relations
- US military engineers said it would take a year to revive pre-war oil output of around three million barrels per day
US troop convoys came under attack twice on Monday with rocket-propelled grenades.
One soldier died in an attack in the prosperous al-Mansur area of Baghdad at 0600 local time (0200 GMT) whilst a second attack just north of the city reportedly left one American and two Iraqis wounded.
US officials have attributed attacks to elements loyal to the ousted regime but on Sunday Arabic media reported a claim by a group purporting to be part of the al-Qaeda Islamic militant network.
Al-Arabiya television aired a taped message from an unidentified person who claimed to be from the "Islamic Armed Group of al-Qaeda, Falluja branch" - a previously unknown organisation.
Paul Bremer, the head of the US administration in Iraq, said in a newspaper interview published on Sunday that the US was braced for new attacks both by Iraqi "bitter-enders" and "an increase in terrorism by