New Zealand Brig. Gen. Hugh McAslan says that the U.S.-led coalition has used white phosphorus in Mosul, Iraq.
McAslan told NPR on June 13: "We have utilized white phosphorus to screen areas within west Mosul to get civilians out safely."
McAslan estimated that about 28,000 civilians managed to leave the area, which is controlled by the Islamic State, in the days just previous to his statement.
The U.S.-led coalition has admitted using the chemical compound in less-populated areas of northern Iraq, but McAslan's comments marked the first time that white phosphorus has officially been used in Mosul.
Amnesty International said that white phosphorus, which bursts into flames when exposed to oxygen, can cause "horrific injuries, burning deep into the muscle and bone."
The chemical compound can also blow up weeks after being dropped, which can threaten civilians who are returning or leaving.
Amnesty International reported on white phosphorus being used east of Mosul in 2016, which the human rights organization said "constitutes an indiscriminate attack and can be a war crime."
Chemical Weapons Convention spokesman Peter Kaiser told BBC News in 2005 that white phosphorus is allowed during wars for "camouflage movement," but added: "If on the other hand the toxic properties of white phosphorus, the caustic properties, are specifically intended to be used as a weapon, that of course is prohibited..."
The U.S. used white phosphorus in Fallujah, Iraq, during a battle in 2004, and again in Afghanistan in 2009, notes NPR.
The ISIS-affiliated Amaq News Agency recently accused U.S.-led forces of using white phosphorus in the fight for Raqqa, Syria, and aired video of the alleged use. That allegation has not been confirmed by Amnesty International.
Amnesty International warned that the use of white phosphorus in Raqqa poses an "unacceptably" high risk to civilians, and may be a war crime.
Steve Goose, arms director at Human Rights Watch, condemned the use of white phosphorus in a press release on June 14:
No matter how white phosphorus is used, it poses a high risk of horrific and long-lasting harm in crowded cities like Raqqa and Mosul and any other areas with concentrations of civilians. US-led forces should take all feasible precautions to minimize civilian harm when using white phosphorus in Iraq and Syria.
An unidentified U.S. official recently told The New York Times that U.S. forces in Iraq and Syria have access to white phosphorus, but are not using the chemical against people.
U.S. Col. Ryan Dillon, a spokesman for the U.S.-led forces, recently said that "white phosphorus rounds are used for screening, obscuring and marking in a way that fully considers the possible incidental effects on civilians and civilian structures."