Two women, aged 20 and 22, have been detained following an incident at the MSPO defence industry fair in Kielce. An acidic substance containing butyric acid was spilled in one of the halls at the fair. The arrests occurred in Mazovia and the Kuyavian-Pomeranian Voivodeship. Authorities are investigating the motives behind the incident and the nature of the substance used. The spill caused disruption at the Kielce trade fair, though the extent of any damage is currently unknown. Further details are expected to be released as the investigation progresses. The incident prompted a response from emergency services and security personnel at the MSPO event in Kielce.