Why kibana is making two indices

Before running kibana instance i deleted all the indices. What is see is kibana is making 2 indices, earlier it was used to create only one .kibana

When changes are necessary, a new incremental .kibana_N index is created with updated mappings, then the saved objects are loaded in batches from the existing index, transformed to whatever extent necessary, and added to this new index.
Once the objects are migrated, the .kibana index alias is updated to point to the new index, and Kibana finishes starting up and serving HTTP traffic.
That's why you are seeing the other .kibana_2 index. The is caused by stopping the process which is in charge of handling the migration. So if you are in the process of migration/upgrade you do see the .kibana_2 index as well.

Hope this helps
Thanks
Rashmi