Münster (dpa / lnw) – In a school center in Münster, 22 schoolchildren received emergency medical care on Thursday after an irritant gas leak. The fire brigade was called at noon after the students complained of nausea or irritation of the respiratory tract, a spokesman said. 19 high school students were treated on site by the emergency services for respiratory irritation, three for discomfort or nausea. It is still unclear whether anyone needs to be taken to the hospital. The operation is still ongoing, the fire brigade spokesman said a good hour after the alarm was raised. Where the irritant gas comes from is also still unclear. The Hauptschule and Realschule belonging to the school complex are not affected.