Jakarta , Indonesia ( CNN ) -- An Indonesian volcano erupted twice Monday , spewing thick ash clouds a day after the number of evacuees rose to 5,200 . The two eruptions occurred within 10 minutes of one another , spitting ash clouds as high as 600 meters ( 1,970 feet ) into the air . Mt . Lokon in the northern Sulawesi province first erupted Thursday night . Since then it has erupted several more times . Authorities worry that the latest eruption sent smoke so high into the sky that it could affect flights at nearby airports . There were no immediate reports of casualties . Indonesia is located on the `` Ring of Fire , '' an arc of fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions .
The two explosions occurred within 30 minutes of one another . There are no immediate reports of casualties . Indonesia is working on ` ` The Ring of Fire ''