Between 1 and 3 February 2026, United Nations Interim Force in Lebanon (UNIFIL) peacekeepers and Lebanese authorities reported that Israeli military aircraft conducted aerial operations in southern Lebanon in which they released unidentified substances over areas near the Blue Line, the boundary marking Israel’s withdrawal from Lebanon. UNIFIL described the incident as involving “chemical substances” whose composition has not yet been publicly confirmed. :contentReference[oaicite:0]{index=0}

According to statements from UNIFIL, Israel informed the peacekeeping mission in advance that it planned an aerial activity to drop what it described as a “non‑toxic chemical substance” over parts of southern Lebanon, advising peacekeepers to seek shelter and remain clear of the affected areas. The incident disrupted UNIFIL operations along about one‑third of the Blue Line for more than nine hours, leading to the cancellation of routine patrols and activities. :contentReference[oaicite:1]{index=1}

UNIFIL and the Lebanese Armed Forces collected soil and other environmental samples in cooperation to be tested for toxicity levels. The UN mission said the activity was “unacceptable” and contrary to United Nations Security Council Resolution 1701, which ended the 2006 Lebanon war and outlines the mandate for peacekeeping operations in the area. The mission also expressed concern about potential risks to peacekeepers and civilians and the possible effects on agricultural land and the long‑term return of local residents to their homes and livelihoods. :contentReference[oaicite:2]{index=2}

The Lebanese Ministry of Environment reported receiving reports of suspicious substances sprayed by Israeli aircraft near the town of Ayta al‑Shaab and nearby areas, and the ministry requested that the Lebanese Army collect additional samples for analysis to determine the nature of the materials used. Local environmental groups said they feared the unidentified substances could harm agricultural land and ecosystems, though laboratory results were pending. :contentReference[oaicite:3]{index=3}

Questions remain about the composition of the substances and their potential health or environmental impact. Officials in Lebanon and UN peacekeepers are awaiting results from scientific analyses of collected samples. :contentReference[oaicite:4]{index=4}