Report: Israeli use of white phosphorus in southern Lebanon between March and May 2026

Human Rights Watch and the International Human Rights Clinic at Harvard Law School on Wednesday released a report documenting 23 verified incidents of Israeli use of white phosphorus in southern Lebanon between March and May 2026, arguing that the findings expose a gap in international law and should spur action at two U.N. disarmament meetings later this year.

The report, titled “Uncontrolled Burn: The Inhumane Effects of White Phosphorus Munitions and the Need for Stronger Law,” is framed not simply as a record of alleged battlefield use, but as a warning that current rules do not specifically regulate white phosphorus through a dedicated treaty. Human Rights Watch and Harvard say governments should take up the issue at the U.N. General Assembly’s First Committee, which handles disarmament and international security issues, in October in New York and at the Convention on Certain Conventional Weapons’ Seventh Review Conference in Geneva on Nov. 16-20.

That timing is central to the report’s argument. The groups say white phosphorus has been reported in conflicts including Gaza, Iraq, Syria, Yemen, Afghanistan and Somalia since 2000, but that the law has lagged behind repeated use. “White phosphorus munitions can inflict excruciating burns and cause lifelong physical, psychological, and socioeconomic harm,” Bonnie Docherty, senior arms adviser at Human Rights Watch and a lecturer at the Harvard clinic, said in a news release.

Human Rights Watch and Harvard said their findings were based on legal analysis, open-source investigation, geolocation and chronolocation of photos and videos, 16 in-person and remote interviews, desk research and monitoring of diplomatic procedures. The report also drew on WhitePhosphorus.info, an open-source archive maintained by Ahmad Baydoun of TU Delft, which Human Rights Watch said it corroborated.

One example cited by Human Rights Watch from its earlier reporting was an incident on March 3 over Yohmor in southern Lebanon. The group said it geolocated imagery showing at least two artillery-fired, air-burst white phosphorus munitions, and that civil defense photos showed fires on at least two homes and one vehicle.

White phosphorus ignites when exposed to oxygen. It produces dense white smoke and burning particles, which is why militaries have described some uses as smoke, obscuration or illumination. But it can also cause deep thermal and chemical burns. Medical literature cited in the report says particles left in wounds can reignite when re-exposed to oxygen, complicating treatment.

The report’s central legal claim is that air-burst white phosphorus used over populated areas is indiscriminate and therefore violates general international humanitarian law. More broadly, it says existing arms-control law leaves many white phosphorus munitions in a gray area.

Protocol III of the Convention on Certain Conventional Weapons restricts incendiary weapons, but applies to munitions “primarily designed” to burn people or set fires. Human Rights Watch says many white phosphorus munitions fall outside that definition because they are often described as intended for smoke, obscuration or illumination. The report also notes that white phosphorus is not treated as a chemical weapon when used for smoke or incendiary purposes, meaning it is not covered by the Chemical Weapons Convention.

Human Rights Watch and Harvard are urging states to press the issue in the coming months, including by raising it at the First Committee and the November review conference for the Convention on Certain Conventional Weapons, a treaty that regulates some weapons considered to cause excessive injury or have indiscriminate effects. The report says the convention’s consensus rule has allowed Russia and other opponents to block dedicated discussions on incendiary weapons and weapons with incendiary effects.

For fairness, the Israeli military response available in the public record is tied to Human Rights Watch’s earlier March 2026 findings, not Wednesday’s report. Contemporaneous press reports at the time quoted the Israeli military as saying it was unaware of and could not confirm claims that it had used white phosphorus in Lebanon, and that it uses legal weapons in accordance with the law.

The report calls for stronger measures, ultimately arguing that the best remedy would be a sweeping prohibition. “A complete ban on production, transfer, stockpiling, and use of these weapons would have the greatest humanitarian benefits,” the recommendations section says.