Georgia’s second-largest school district says that it has removed two books from 20 school libraries, saying the books had “highly inappropriate, sexually explicit content.”

The announcement, sent in an electronic message to parents in some Cobb County schools on Monday, comes days after the Republican-majority school board voted 4-3 along party lines to fire a teacher for reading a book about gender identity to fifth-grade students.

Although not new, book removals have surged since 2020, part of a backlash to what kids read and discuss in public schools. Conservatives want to stop children from reading books with themes on sexuality, gender, race and religion that they find objectionable. PEN America, a group promoting freedom of expression, counted 4,000 instances of books banned nationwide from July 2021 to December 2022.