With the recent implementation of China’s controversial security law in Hong Kong, books with pro-democracy content will now be removed from public libraries and reviewed according to the new measure imposed.

At least nine books have already been removed and are marked for review in the city’s online library catalog. The security law raises concerns that authorities will begin censoring literature and the media and the Internet, the Wall Street Journal reported.

Among the censored books is one by well-known Hong Kong activist Joshua Wong and another by Tanya Chang, a legislator who is also known for her defense of democracy.

The Department of Cultural Services said that “In the review process, the books will not be available for borrowing and reference.”

Last Monday, the Education Bureau said schools should also get rid of reading materials that “possibly violate” the new legislation, while at the same time suggesting that students should learn what they called the positive values of safeguarding national security.

The aforementioned security law imposed on Hong Kong from the mainland came into force on June 30 and aims to prohibit any act of secession, subversion, terrorism, and collusion with a foreign country or other elements.

As the Guardian points out, the Chinese authorities assure that they will restore stability after a year of pro-democracy protests, and “… will not stifle freedoms and focus only on a ‘very small’ minority.

However, arrests and attacks on those who defend slogans in favor of democracy, independence and greater autonomy are beginning to spread fear in the streets of the city.

Meanwhile, law groups, and legal analysts point out that the general wording of the security law, kept secret until it is publicly disclosed, also censors certain political opinions, even when expressed peacefully.

The law now in force in Hong Kong has so far resulted in 10 people being arrested for allegedly violating the new measure’s provisions.

As the BBC points out, the new law allows for closed trials, wiretapping of suspects, and the possibility of being tried in mainland China.

At the same time, there are concerns that the law may affect online freedom as providers could hand over data if requested by the authorities.