Searching Arabic content: getting only exact matches

I am using Logstash 2.3.3, Elasticsearch 2.3.3, Kibana 4.5.3.
The content for search is in Arabic (Unicode utf-8).
Currently the search only finds exact words, not according to stem.

For example, the word in Arabic ‘ باب’ ‘door’ and ‘الباب ‘ ‘the door’ are considered two separate words and searching for ‘door’ ‘ باب’ will not get instances of ‘the door’ ‘الباب ‘ .

Any hint on how to solve this problem?
Thanks in advance

You have to set the analyzer to arabic language for the field: