Remnants of a US-produced white phosphorous smoke round found in Dheira, Lebanon. (The Washington Post)

Israel used US-supplied internationally banned white phosphorus munitions in an October attack in southern Lebanon, according to a Washington Post investigation.

A journalist working for The Post found remnants of three 155-millimeter artillery rounds fired into Dheira, near the Lebanese border with Israel, which wounded at least nine civilians and incinerated at least four homes, residents said, the newspaper said.

Lot production codes found on the shells match the nomenclature used by the US military to categorize domestically produced munitions, which show they were made by ammunition depots in Louisiana and Arkansas in 1989 and 1992, the report said.

The light green color and other markings - like WP printed on one of the shells - are consistent with white phosphorous rounds, according to arms experts cited by the publication.

Photos and videos verified by international rights groups and reviewed by The Post show the characteristic ribbons of white phosphorus smoke falling over Dheira on October 16.

Israeli forces continued to shell the town with white phosphorus munitions for hours, residents said, trapping them in their homes until they could escape around 7 a.m. the next morning. Residents now refer to the attack as the black night.

The US origin of the shells was verified by Human Rights Watch and Amnesty International.

Shortly after the October attack, Human Rights Watch said it had verified footage taken in Lebanon and Gaza showing multiple uses of artillery-fired white phosphorus over the Gaza City port and two rural locations along Lebanon’s border.

The same manufacturing codes also appear on white phosphorus shells lined up next to Israeli artillery by the city of Sderot, near the Gaza Strip, in an October 9 photo.

The Crisis Evidence Lab at Amnesty International said they corroborated the authenticity of videos and photos depicting the utilization of white phosphorus smoke artillery shells in Dhayra on October 16.

The rounds, which eject felt wedges saturated with white phosphorous can stick to the skin, causing potentially fatal burns and respiratory damage, and its use near civilian areas could be prohibited under international humanitarian law.

Tirana Hassan, the executive director of HRW, said US Congress should take reports of Israel’s use of white phosphorus seriously enough to reassess US military aid to Israel.

The weapons are part of billions of dollars in annual US military assistance to Israel.

Israel has killed nearly 18,000 people, a huge number of whom children, in Gaza since October 7.