BEIRUT (AP) — The U.S.-led coalition fighting the Islamic State group in Iraq and Syria is endangering civilians by using artillery-delivered white phosphorous, Human Rights Watch said Wednesday, after reports that such weapons were used in the Syrian city of Raqqa.
HRW said it was not able to independently verify whether the use of the munitions resulted in any civilian casualties. The U.S. military says it uses white phosphorous in a lawful way.
White phosphorous burns at extremely high temperatures and can be used to illuminate conflict zones or obscure them with smoke. International law prohibits its use in civilian areas because of its indiscriminate effects, from starting fires to causing excruciating burns for bystanders, according to Human Rights Watch.
"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," said Steve Goose, arms director at Human Rights Watch. "U.S.-led forces should take all feasible precautions to minimize civilian harm when using white phosphorus in Iraq and Syria."
The Islamic State group is under attack in the northern Iraqi city of Mosul and in Raqqa, the extremist group's de facto capital. In Mosul, a coalition of Iraqi military and pro-government militias has taken the eastern half of the city and is shrinking the IS footprint in the western half. In Raqqa, the campaign to retake the city began in earnest last week, led by the Kurdish-dominated Syrian Democratic Forces.
HRW, citing research and media reports, referred to several incidents in Raqqa and Mosul where artillery-fired white phosphorous was used. The group said the rationale for the use of the weapon is unclear as the U.S.-led coalition doesn't comment on specific incidents.
In a video released through its Aamaq news agency, IS said the U.S.-led coalition used white phosphorous over Raqqa last Thursday at dusk, when Muslims would have been breaking their Ramadan fasts.
The U.S. military refused to comment on specific allegations after last week's attack in Raqqa but said it uses white phosphorous rounds "in accordance with the law of armed conflict ... in a way that fully considers the possible incidental effects on civilians and civilian structures."
HRW said U.S.-led forces in Mosul and Raqqa are using U.S.-made M825-series 155mm artillery projectiles containing 116 felt wedges impregnated with white phosphorus, which ignites and continues to burn when exposed to the air. This is the only type of 155mm white phosphorus projectile in U.S. stocks that can be air-burst, HRW said.
Neither IS nor Syrian government forces are known to possess or to have used the U.S.-made munitions, it said.
On Wednesday, the Syrian Observatory for Human Rights said the Kurdish-led forces leading the campaign have advanced west of Raqqa city under intense airstrikes by the U.S-led coalition. So far the anti-IS forces have advanced from the west and east, fully controlling or entering at least four Raqqa neighborhoods.