The United States military has defended its use of white phosphorus against insurgents in Iraq, but denies having used it against civilians.

US Marines taking a prisoner in Fallujah (2003 photo)

Pentagon spokesman Bryan Whitman told reporters Wednesday that white phosphorus is a conventional weapon, not a chemical one, and is used mainly as a smokescreen or to mark targets. But he said it is also used against enemy combatants, including last November during an offensive to oust insurgents from their stronghold in the city of Fallujah.

An Italian television documentary, aired last week, accused the U.S. military of killing civilians in Fallujah with white phosphorus, which is flammable and can cause serious burns.

The Pentagon official disputed the accusation, saying the U.S. military does not target civilians. White phosphorus is not banned by any treaty to which the United States is a signatory.

British military officials also confirmed their troops in Iraq have used white phosphorus as a smokescreen cover.