The unexpectedly large number of American and British casualties in the war against Iraq has shocked the coalition forces, media reports said on Tuesday.

"The first days of the war in Iraq were so smooth. Americans might have been forgiven for imagining that the conflict would be clean and relatively free of casualties on the coalition side," the New York Times noted in an editorial.

Referring to the 19 deaths on the coalition side in chopper crashes, it said, "Such losses had not been expected."

The Washington Post said, "The losses were painful for American and British service men and women… the costliest in combat for the American military since Somalia in 1993 or maybe even since the Persian Gulf War.

"The hopes of a quick regime collapse have dissipated as some Iraqi forces have fought back. The regime has also recovered from its early disarray to reprise some of its Gulf War propaganda tactics," the paper opined.

Some coalition soldiers were captured and many killed in fighting in southern Iraq. On Saturday, a US soldier at a base in Kuwait, a recent convert to Islam, killed a colleague and wounded 12 others by lobbing hand grenades into their tents.

Two British airmen were missing after their Tornado bomber was shot down unintentionally by a US Patriot missile near the Kuwaiti border.

The Washington Post described the state of US prisoners of wars as "sobering" and said: "The images beamed around the world of US soldiers in stunned captivity or dead in a makeshift morgue in southern Iraq cast some doubt on the assumptions underpinning the American approach."