MOSCOW (AP) — Russian authorities have burned more than 50 books and pulled more than 500 other volumes from college libraries on the grounds they contain sentiments "alien to Russian ideology."

The books, most of them humanities textbooks, were published with money from the Soros Fund, which in November was declared an "undesirable agent" and forced to stop its work in Russia.

The books were removed from libraries in two colleges in the northwestern Komi region and some were later burned in the school's courtyard.

The Komi education minister said in a letter dated Wednesday that the books were destroyed to fulfill an order from a presidential envoy requesting that books published with funds from the Soros Fund be removed from circulation. The letter was sent to a local news site in response to its request for information.

The federal cultural minister told reporters on Thursday that he was unaware of the incident, but said he realizes burning books would be a mistake.

"In principle, book burning is akin to destroying monuments. It looks very bad and conjures strange historical associations which, in my opinion, are totally unacceptable," said Culture Minister Vladimir Medinsky, according to reports from the Tass news agency.