The agriculture and environment ministries said laboratory tests confirmed the substance was glyphosate, a chemical used to destroy vegetation, with concentrations in some samples "between 20 and 30 times the levels usually accepted".

President Joseph Aoun condemned the spraying of what he described as "toxic substances", calling it a violation of Lebanese sovereignty and an environmental and health crime.

The Israel Defense Forces (IDF) told the BBC they had no comment on the matter.