What is white phosphorus, and why is it reportedly being used in Lebanon?

White phosphorus is a chemical substance that ignites on contact with oxygen, producing intense heat, bright light and thick, toxic smoke, according to Al Jazeera.

The substance can cause severe burns to human skin and tissue, and because it can reignite if exposed to air after initial contact, injuries from white phosphorus are notoriously difficult to treat.

Military forces have historically used white phosphorus for purposes including creating smoke screens to obscure troop movements and illuminating battlefields, and, more controversially, as an incendiary weapon, which has drawn criticism from human rights groups when used in populated areas.

Reports have pointed to its use in Lebanon amid the broader conflict involving Israel, raising concerns among humanitarian organizations about the risks posed to civilians in affected areas.

International law restricts the use of incendiary weapons like white phosphorus near concentrations of civilians, though enforcement in active conflict zones remains difficult, and the specific circumstances of its reported use in Lebanon were not independently detailed in the report.