Israeli forces spray unknown chemical on southern Lebanon, forcing UN peacekeepers to halt operations

The United Nations Interim Force in Lebanon (UNIFIL) has warned of serious health and environmental risks after Israeli forces dispersed an "unknown chemical substance" over areas near the Blue Line in southern Lebanon, forcing the suspension of peacekeeping operations for several hours.

In a statement posted on X on Monday, UNIFIL said Israeli forces notified the mission early on Sunday of a planned aerial operation involving the dispersal of a chemical substance near the UN-demarcated line marking Israel's withdrawal from Lebanon in 2000.

According to UNIFIL, Israeli forces instructed peacekeepers to withdraw from the area and remain under cover, leading to the cancellation of more than a dozen field activities.

"Peacekeepers could not perform normal operations near the Blue Line along about a third of its length and were only able to resume normal activities after over nine hours," the statement said.

UNIFIL added that it supported the Lebanese army in collecting samples from affected areas for toxicity testing, after Israeli forces asserted that the substance was non-toxic.

The peacekeeping force described the incident as "unacceptable" and said it constituted a violation of UN Security Council Resolution 1701, which ended the 2006 war between Israel and Hezbollah and governs military conduct along the border.

"[Israeli forces] deliberate and planned actions not only restricted peacekeepers from carrying out their mandated duties, but also may have placed both personnel and civilians at risk," UNIFIL said.

It added that the operation raised serious concerns over the potential impact of the chemical substance on agricultural land near the border, as well as the long-term consequences for civilians attempting to return to their homes and livelihoods.

UNIFIL noted that this was not the first instance in which Israeli aircraft had dispersed unidentified chemical substances over Lebanese territory, and urged Israel to halt such actions and comply with its obligations to allow peacekeepers to operate safely and effectively in southern Lebanon.

Separately, Lebanon's environment minister, Tamara Zein, said she had contacted army commander Rodolphe Haykal after receiving reports from the border town of Aita al-Shaab and surrounding areas that Israeli aircraft had sprayed chemical or pesticide-like substances.

In a statement, Zein said samples had been requested from affected sites for laboratory analysis to determine the nature of the materials used, adding that if toxicity were confirmed, such conduct would be consistent with previous Israeli practices in the area.

The incident comes amid growing concern over environmental destruction in southern Lebanon, where repeated Israeli bombardment, the documented use of white phosphorus, the clearing of farmland, and contamination from unexploded ordnance have caused widespread damage to forests, agricultural land, and water sources.

Israeli attacks have continued in southern Lebanon despite a ceasefire agreement reached late last year, prompting concern among UN officials and rights groups over the systematic degradation of the environment and the long-term ecological harm inflicted on border communities.

These strikes form part of a wider Israeli campaign that has repeatedly targeted reconstruction efforts in southern Lebanon, targeting rebuilding work and effectively preventing displaced southern residents from returning to their homes.