US troops used white phosphorus as a weapon in last year's offensive in the Iraqi city of Falluja, the US has said. "It was used as an incendiary weapon against enemy combatants," spokesman Lt Col Barry Venable told the BBC - though not against civilians [Yeah, right!], he said. The US had earlier said the substance - which can cause burning of the flesh - had been used only for illumination. BBC defence correspondent Paul Wood says having to retract its denial is a public relations disaster for the US.