They are written in thuluth and kufic script with blue letters. Based on the remaining letters and some words, it has been established that the inscriptions contained monotheistic formulas «Kalima-i tayyiba» and «Kalima-i shahadat», kufic script. The following text is in the round cartouches, thuluth script: – In the name of Allah, and His names. In the center of the cartouches it is written الله «Allah». Along the perimeter of the cartouches, there is a name of the Prophet Muhammad, and the names of the four khalifs: Abu Bakr, Umar, ‘Usman, ‘Ali.
You can learn more about the topic in the book-album "Architectural epigraphy of Uzbekistan. Qashqadaryo, Shahrisabz" of the series "Architectural epigraphy of Uzbekistan".