The Texas State Board of Education greenlit a new social studies curriculum on Friday that will teach high school students about how Islam is "radical" and "brutal".

The move followed several hours of testimony by hundreds of people before the Republican-dominated board made its 8-4 decision about how to amend the way religions are taught across public schools in the state.

The new curriculum will affect some five million students.

Starting in the 2030-2031 school year, when the textbooks are phased in, the focus will shift to making Bible passages required reading, highlighting Christianity's positive attributes, and referring to early Islam's military campaigns as "brutal" despite not using the same term to describe wars waged by Christians.

Teaching early Islam will be specifically framed through a lens of slavery and female captivity, the Fox4 Dallas-Fort Worth news channel reported.