Since the war began in March, 1,124 have been wounded in action.

The numbers have grown so large and attacks have become so commonplace that the United States Central Command usually issues press releases listing those injured only when the attacks kill one or more troops.

The result is that many injuries go unreported.

The rising number and quickening pace of soldiers being wounded on the battlefield have been overshadowed by the number of troops killed since President George W. Bush declared an end to major combat operations on May 1.

But alongside those Americans killed in action, an even greater toll of battlefield wounded continues unabated.

An increasing number are being injured through small-arms fire, rocket-propelled grenades, remote-controlled mines and what the Pentagon refers to as 'improvised explosive devices'.

In the latest incident, four US soldiers were wounded on Tuesday afternoon when their convoy struck an 'improvised explosive device' near Saddam Hussein's home town of Tikrit.

Indeed, the number of troops wounded in action in Iraq is now more than twice that of the Persian Gulf War in 1991.

The total increased more than 35 per cent last month - with an average of almost 10 troops injured a day.