KABUL - Doctors voiced concern over "unusual" burns on Afghan villagers wounded in an already controversial U.S.-Taliban battle, and the country's top human rights groups said Sunday it is investigating the possibility white phosphorus was used.
The American military denied using the incendiary in the battle in Farah province - which President Hamid Karzai has said killed 125 to 130 civilians - but left open the possibility that Taliban militants did. The U.S. says Taliban fighters have used white phosphorus, a spontaneously flammable material that leaves severe chemical burns on flesh, at least four times the last two years.
Using white phosphorus to illuminate a target or create smoke is considered legitimate under international law, but rights groups say its use over populated areas can indiscriminately burn civilians and constitutes a war crime.
Afghan doctors told The Associated Press they have treated at least 14 patients with severe burns the doctors have never seen before. The villagers were wounded during last Monday's battle in Farah province.
Allegations that white phosphorus or another chemical may have been used threatens to deepen the controversy over what Afghan officials say could be the worst case of civilian deaths since the 2001 U.S. invasion that ousted the Taliban regime.
In Kabul on Sunday, hundreds of people marched near Kabul University to protest the U.S. military's role in the deaths. Protesters carried signs denouncing the U.S. and chanted anti-American slogans.
The incident in Farah drew the condemnation of Karzai, who called for an end to airstrikes. The U.S. has said militants kept villagers captive in hopes they would die in the fighting, creating a civilian casualties controversy.
However, President Barack Obama's national security adviser said Sunday the United States would not end airstrikes. Retired Gen. James Jones refused to rule out any action because "we can't fight with one hand tied behind our back."
Along with Afghan and U.S. investigations into the battle, the Afghan Independent Human Rights Commission has been looking into concerns that white phosphorus may have been used after strange burns were reported. Nader Nadery, a commissioner in the leading rights organization, said more investigation was needed.
"Our teams have met with patients," Nadery told AP. "They are investigating the cause of the injuries and the use of white phosphorus."
White phosphorus is a spontaneously flammable material that can cause painful chemical burns. It is used to mark targets, create smoke screens or as a weapon, and can be delivered by shells, flares or hand grenades, according to GlobalSecurity.org.
Human rights groups denounce its use for the severe burns it causes, though it is not banned by any treaty to which the United States is a signatory.
The U.S. military used white phosphorus in the battle of Fallujah in Iraq in November 2004. Israel's military used it in January against Hamas targets in Gaza.
Col. Greg Julian, the top U.S. military spokesman in Afghanistan, said the U.S. did not use white phosphorus as a weapon in last week's battle. The U.S. does use white phosphorous to illuminate the night sky, he said.
Julian noted that military officials believe that Taliban militants have used white phosphorus at least four times in Afghanistan in the past two years. "I don't know if they (militants) had it out there or not, but it's not out of the question," he said.
A spokesman for the Taliban could not be reached for comment Sunday.
The U.S. military on Saturday said that Afghan doctors in Farah told American officials the injuries seen in wounded Afghans from two villages in the province's Bala Baluk district could have resulted from hand grenades or exploding propane tanks.
Dr. Mohammad Aref Jalali, the head of the burn unit at the Herat Regional Hospital in western Afghanistan who has treated five patients wounded in the battle, described the burns as "unusual."
"I think it's the result of a chemical used in a bomb, but I'm not sure what kind of chemical. But if it was a result of a burning house - from petrol or gas cylinders - that kind of burn would look different," he said.
Gul Ahmad Ayubi, the deputy head of Farah's health department, said the province's main hospital had received 14 patients after the battle, all with burn wounds. Five patients were sent to Herat.
"There has been other airstrikes in Farah in the past. We had injuries from those battles, but this is the first time we have seen such burns on the bodies. I'm not sure what kind of bomb it was," he said.
U.N. human rights investigators have also seen "extensive" burn wounds on victims and have raised questions about how the injuries were caused, said a U.N. official who asked not to be identified talking about internal deliberations. The U.N. has reached no conclusions about whether any chemical weapons may have been used, the official said.
Afghan officials say up to 147 people may have died in the battle in Farah, though the U.S. says that number is exaggerated.
The investigation into the Farah battle coincides with an appeal by Human Rights Watch for NATO forces to release results of an investigation into a March 14 incident in which an 8-year-old Afghan girl was burned by white phosphorus munitions in Kapisa province.
The New York-based group said Saturday that white phosphorus "causes horrendous burns and should not be used in civilian areas."
In the latest violence, a double suicide bomb attack killed seven people and wounded 20 in southern Afghanistan on Sunday. The majority of casualties were police and army units responding to the initial attack, said Dawood Ahmadi, the governor's spokesman.
A roadside bomb in eastern Nangarhar province killed eight construction workers traveling on a rural road on their way to build a checkpoint for the country's border police, an official said, while a truck driver and two assistants died in a roadside bomb blast in Zabul province while transporting goods to a U.S. base, police said.
Taliban militants have increased their attacks the last three years as the country's insurgency has turned increasingly bloody. President Barack Obama is sending 21,000 additional U.S. troops to the country to bolster the record 38,000 American forces already in the country.