Florida’s education department has rejected 54 mathematics textbooks from next year’s school curriculum, citing alleged references to critical race theory among a range of reasoning for some of the rejections, officials announced.

The department said in a news release Friday that some of the books had been rejected for failure to comply with the state’s content standards, Benchmarks for Excellent Student Thinking [Best], but that 21% of the books were disallowed “because they incorporate prohibited topics or unsolicited strategies, including CRT”.

Department officials disapproved an additional 11 books “because they do not properly align to Best Standards and incorporate prohibited topics or unsolicited strategies, including CRT”.

Critical race theory is an academic practice that examines the ways in which racism operates in US laws and society.

The release does not list the titles of the books or provide any extracts to offer reasons why the books were removed. The announcement follows a series of hardline measures by Republicans in the state to alter teaching in schools as conservatives thrust the issue of critical race theory into the country’s ongoing political culture wars.

In June last year, the Florida board of education ruled to ban the teaching of critical race theory in public schools. That included the teaching of the New York Times’s Pulitzer prize-winning series the 1619 Project, which re-examines American history in the context of slavery and its consequences.

In a statement, Florida’s Republican governor Ron DeSantis welcomed the education department’s announcement and accused some textbook publishers of “indoctrinating” children with “concepts like race essentialism, especially, bizarrely, for elementary school students”.

Florida Democrats rebuked the announcement. Democratic state representative Carlos G Smith argued on Twitter that DeSantis had “turned our classrooms into political battlefields and this is just the beginning”.

Swathes of Republican-controlled states in the US have passed measures seeking to ban the teaching of critical race theory, which will probably be a prominent conservative talking point in this year’s midterm elections.

Many of those bills and orders are vaguely worded, leading to fears of censorship on school and college campuses around the country.