First of all, I wanna thank all of you for your help. I do some research on this subject and I find some interesting things.
I know about Bogomils and their graveyard (called Stecci)... Maybe those realy are stecci. In Bosnia there are a lots of them on every step. Even near my home there are two of them. But I think that stecci are different shape, size, sarcofage look like etc. everything that makes stecci unique in the world. You will see the difference...
You can see pictures here:






Very interesting pictures. Thank you for shareing them.
Those two are with "swastika". Second picture is near Ugljevik (vilagge Priboj)


You can notice the difference...
If you watch movie that I give a link for you will notice a lots of maltese crosses as a symbol on a headstones... even this strange symbol that I show you here look like some version of maltese cross. Isn't that? I am not shure but I think that MALTESE CROSS is symbol that use KNIGHTS TEMPLAR...
Stop the video at 01:40 and 02:14 and you will strange cross wich in heraldic have name called "Cross of Lorraine". Again that cross is symbol that use KNIGHTS TEMPLAR...
On 02:56 you will notice circle and cross within. In heraldic called "Sun Cross". One of the oldest crosses, and Celtic cross is variaty of this cross.
Pagan symbols on 02:00 and 02:19(rune or "Y" cross)...
But most strange thing is that I never find some archeological and historical fact about this graveyard in the books...