Ukrainian President Volodymyr Zelensky on Thursday accused Russia of using white phosphorus munitions during its assault. Video released by the British channel ITV corroborates the claim, showing streaks of bright light falling over the Kyiv suburb of Irpin earlier this week. White phosphorus ignites on contact with oxygen and burns at extremely high temperatures. It’s fat-soluble, easily absorbed through the skin and can melt through flesh. Russia previously used white phosphorus in attacks on Chechnya. The incendiary is often called “Whiskey Pete” by the U.S. military, which used the substance in Korea, Vietnam, Iraq, Afghanistan and Syria. In 2004, U.S. Marines used white phosphorus as an offensive weapon in Fallujah, Iraq. Such use violates international laws on chemical weapons.