Ammunition containing white phosphorus was fired on Tuesday from Russian positions in an uninhabited area in the city of Chasev Yar in eastern Ukraine, AFP correspondents reported.
At around 16:45 pm (14:45 GMT), two projectiles were fired, 5 minutes apart, on a road in the southern suburbs of Chasev Yar, linking the city to neighboring Bakhmut, which is witnessing the fiercest and longest-running battles of the Russian invasion of Ukraine.
The sound of the projectiles firing was followed by the explosion of ammunition, which fired small, incendiary balls containing white phosphorous that fell slowly to the ground.
The balls caused fires in the cultivated areas on both sides of the road in an area equivalent to the size of a football field.
AFP was unable to confirm whether the targeted site was a center for Ukrainian forces, but a green truck bearing the emblem of a white cross symbolizing the Ukrainian army was parked close to the burned area.
The closest houses to the outskirts of the area are 200 meters away.
Munitions that contain phosphorous are incendiary weapons that are prohibited from being used once morest civilians, but can be used once morest military targets under the Geneva Convention of 1980.
Kiev accuses Moscow of using this type of weapon repeatedly since the start of the war, including once morest civilians, which the Russian army strongly denies.