( CNN ) Chile 's Calbuco volcano erupted twice in 24 hours , the country 's National Geology and Mining Service said early Thursday . The agency said it was evaluating the spectacular nighttime eruption , but indicated it was `` stronger than the first one . '' About 23½ inches ( 60 centimeters ) of ash fell in some places , according to the Ministry of Interior and Public Safety . Authorities issued a red alert for the towns of Puerto Montt and Puerto Varas in southern Chile . Both are popular tourist destinations . A 12-mile ( 20 kilometer ) exclusion zone was established around the crater . Military and police forces were assisting with the evacuations of more than 4,400 residents , the Interior Ministry said . The first eruption on Wednesday set off a bit of a panic in the region . `` At the beginning , it was small , and later , the cloud grew and later there was a huge cloud over you and true terror starts , '' said one Puerto Montt resident . Another person said : `` It was impressive to see an enormous mushroom cloud , with the immense force of the volcano , and to see the ashes . At that point , there was a lot of panic , lots of chaos , traffic jams , people going to supermarkets , everyone looking for water , trying to take out money from the ATMs . '' The eruption is a first for many in the region . The last major eruption was 1962 . There was a minor eruption in 1972 . Calbuco also belched out a bit of gas and smoke in 1996 . Alejandro Verges , regional director at the Ministry of Interior and Public Safety , said Thursday afternoon that officials are concerned there might be a third eruption . `` The situation is relatively calm right now , although people are understandably anxious about what could happen tonight , '' he said . CNN 's Shasta Darlington and Marilia Brocchetto contributed to this report .
Almost 2 feet of ash fell in some areas . Authorities evacuate more than 4,400 people . The last time Calbuco erupted was 1972 .