WASHINGTON (Reuters) - The Pentagon on Wednesday acknowledged using incendiary white-phosphorus munitions in a 2004 offensive against insurgents in the Iraqi city of Falluja and defended their use as legal, amid concerns by arms control advocates. ADVERTISEMENT Army Lt. Col. Barry Venable, a Pentagon spokesman, said the U.S. military had not used the highly flammable weapons against civilians, contrary to an Italian state television report this month that stated the munitions were used against men, women and children in Falluja who were burned to the bone.