Mount Bromo showed signs of increasing activity beginning in 4th Dec 2015, when the amount of smoke coming out of the crater intensified. By late November Mount Bromo began to eject ashes into the air. Indonesian Volcano Monitoring Bureau (PVBMG) issued a warning that forbade people from climbing Mount Bromo. Later the warning was extended into a 1 km exclusion zone, before eventually extended into wider range which virtually barred visitors from coming down into the caldera floor, which is popularly known as Sandsea.