The condolence letter states:

I am shaken by the news about the bloody assault in the Güngören District of Istanbul which resulted in tenths of dead and wounded peaceful and innocent citizens. Please accept mine and of all members of the Bulgarian parliament sincerest condolences and sympathy with the pain of the families and relatives of the victims. I hope for the fastest recovery of the injured.
This last senseless and vicious encroachment on human life casts gloom not only upon Turkey but upon the efforts of the democratic community of the world as a whole.
Bulgaria sharply and decisively denounces the terrorist attack as inadmissible violation of democracy and contemporary civilization. I believe that this brutal act will double the energy of the institutions and the civil society in the region to fight terrorism without compromise.