The U.S. military has accused Taliban militants of using white phosphorus in attacks in eastern Afghanistan.
The U.S. military on Monday declassified documents showing at least 38 instances in which militants used white phosphorus in attacks or white phosphorus weapons were found in stockpiles. The NATO-led force in Afghanistan supplied information on six other instances.
The Associated Press quoted the U.S. military as saying it had documented at least seven cases of militants using white phosphorus in bomb attacks since early 2007, sometimes in populated areas.
Afghanistan's independent human rights commission is investigating whether white phosphorus was used in a battle last week between U.S. and Taliban forces in western Farah province, in which a number of civilians were killed.
The commission said doctors in the province treated patients who suffered severe burns in the fighting. The U.S. military and the Taliban both deny using white phosphorus munitions in Farah.
White phosphorus is a flammable material whose use is considered legitimate under international law for the purposes of illuminating a target or creating a smokescreen in battle.
Rights groups say the military use of white phosphorus in populated areas puts civilians at risk of severe burns and may constitute a war crime. White phosphorus, an alternative form of the element, phosphorus, is unstable and combusts spontaneously when exposed to air.
Afghan President Hamid Karzai has said up to 130 civilians were killed in U.S. air strikes during the Farah battle. He has demanded the U.S. military end such attacks.
But the U.S. military says that although preliminary findings show a number of civilians were killed in the fighting in Farah, militants are to blame for some of the deaths.