Army brass have sent a warning to medical personnel about the soon-to-be-aired Home Box Office documentary Baghdad ER, which gives a graphic view of the Iraq war through the eyes of trauma doctors and nurses, even filming during an amputation.

Despite many disturbing scenes, filmmaker Jon Alpert said the film had been toned down.

"Some of the real raw scenes were just a little bit too brutal. My first two days there, I witnessed four amputations," said Alpert.

A private screening was held in Washington on Monday, and the film will air on the HBO cable television network on Sunday.

Around the US, it will be shown at 22 US military installations, but military medical officers are concerned that it may spark adverse reactions among those suffering from post-traumatic stress disorder.

Nightmares

The army surgeon-general, Lieutenant-General Kevin Kiley, sent out a memo last week warning the film may prompt flashbacks or nightmares.

"It's gritty," said army spokesman Paul Boyce. "It's graphic at times, and those who have a loved one deployed or may have lost a loved one might find certain scenes to be such that it might be something they would want to be careful about in viewing."

Bombings are the biggest cause of casualties

The film records two months at the 86th Combat Support Hospital in Iraq, where medical teams treat those wounded by improvised explosive devices.

Filmmakers Alpert and Matthew O'Neill were given access to the hospital, and the result, Alpert said, "is a very patriotic film".

"It shows the true consequences of war. Americans haven't had the chance to be able to see some of the consequences. It shows the heroism of the soldiers, and you can't understand the heroism of the doctors and soldiers unless you see the horror that they face every day," said Alpert