Rescuers work to free five cavers trapped in Moravian Karst

Firefighters are working to bring five amateur cavers to safety after they became trapped underground in the Moravian Karst, southeast of Brno. The group is reportedly uninjured and just around 100 metres from an exit, but separated from safety by an area with dangerously high carbon dioxide levels. Rescuers say the section can only be crossed using breathing equipment. Higher concentrations of the gas can occur naturally in some cave systems, especially during warmer weather. The Moravian Karst is home to an extensive network of caves, many of them inaccessible to the public.