UN spokeswoman Marie Okabe said the United Nations "welcomes the decision of the government of Iraq to launch an immediate investigation" into the matter.
The Pentagon has confirmed that U.S. troops have used the toxic agent in missions against Iraqi insurgents, but has also defended its use in such operations saying it does not target civilians.
The Pentagon has said it had no knowledge of any civilian victims of attacks with white phosphorus.
Italy's state television RAI claimed last week the highly flammable munitions were used against insurgents and civilians in the Iraqi Sunni town of Al-Fallujah in November last year.
RFE/RL Iraq Report
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