There is credible evidence suggesting that Iranian security forces deployed chemical substances to suppress opposition demonstrators, according to a report from U.K. officials.

The report was referenced during a broadcast on the UK’s GB News. 

British Labour Party foreign policy spokesperson Bill Esterson said the information stems from a credible internal document pointing to the use of a toxic agent against crowds in one of Iran’s major cities. Testimonies highlighted in the report indicate that exposure to the substance did not always lead to immediate effects; instead, some victims suffered delayed health reactions, with fatalities occurring days after contact.

Eyewitness accounts and analysts featured on the program said that the number of people affected is believed to be significant, though precise figures are unclear. British journalist Patrick Christys emphasized during the discussion that the delayed onset of symptoms complicates efforts to quickly identify what was used, drawing international attention to the issue.

The alleged deployment of toxic agents has stirred uncomfortable historical comparisons. Commentators referenced past chemical attacks in the Middle East, including the notorious Halabja massacre under Saddam Hussein and reported chemical use by Syrian government forces, underscoring the severity of such allegations.