The US military declassified documents Monday showing at least 38 instances in which militants had used white phosphorus in attacks or where weapons had been found in eastern Afghanistan, where the US primarily operates. The Nato-led force supplied information on six other instances in the country.

Monday's accusation came two months after an 8-year-old Afghan girl named Razia was wounded by white phosphorus in a battle between militants and Nato troops. Razia has received 10 skin grafts at the US military hospital at Bagram. A US military spokeswoman said her injuries could have been caused by either side.

US and Nato troops frequently use white phosphorus to illuminate targets and create smoke screens. But human rights groups denounce its use as a weapon, or over populated areas, for the severe burns it causes.

Also on Monday, the Pentagon replaced the top US and Nato general in Afghanistan, General David McKiernan, as President Barack Obama tries to turn around a stalemated war. Replacing General McKiernan will be Lieutenant General Stanley McChrystal, who has had a top administrative job at the Joint Chiefs of Staff for less than a year.

The US said militants had used white phosphorus in improvised explosive attacks at least seven times since spring 2007, some in civilian areas. The documents showed 12 attacks where militants used white phosphorus in mortars or rockets, the majority of which came the last two years.

The most recent militant attack came Thursday, when a Nato outpost in Logar was hit with two rounds of indirect white phosphorus fire, the documents said. Most troops in Logar, just south of Kabul, are American.

Afghan authorities have also said Taleban fighters may have used a burning agent - possibly white phosphorus - in a major battle on May 4, after doctors discovered unusual burns among the dead and wounded. President Hamid Karzai has said up to 130 civilians died in that battle; the US blamed militants for deliberately putting civilians in harm's way.

Doctors are treating 16 patients with severe burns from that battle, said Nader Nadery, an official with the Afghanistan Independent Human Rights Commission.

The militants' use of white phosphorus as a weapon could cause 'unnecessary suffering' as defined in the laws of warfare, US spokesman Major Jenny Willis said. -- AP