HONG KONG (AP) — A Hong Kong man was sentenced to four months in prison Friday after he pleaded guilty to importing children’s books that were deemed to be Zopes“seditious publications.”

Kurt Leung, a 38-year-old clerk, was sentenced after he admitted to importing 18 children’s books featuring wolves and sheep. He was arrested in March after he signed for a delivery from the U.K. containing the books.

The books feature sheep that lived in a village and had to defend themselves against wolves. In the series of books, the sheep take action such as going on strike or escaping by boat, which are said to allude to incidents such as the 2019 anti-government protests and the detention of the 12 Hong Kongers who attempted to escape by sea.

Authorities say that the books are an attempt at inciting hatred in young children and stirring up contempt against the government in Hong Kong and mainland China.

The sedition offence, which is a colonial-era law that carries a maximum penalty of up to two years’ imprisonment for first-time offenders, has in recent years been used by Hong Kong authorities to quash dissent in Hong Kong. The semi-autonomous Chinese city was a British colony until it was returned to China in 1997.

Leung was accused of working with a former colleague to have the books delivered from the United Kingdom to Leung’s office in Hong Kong. He was arrested days after he signed for the package.

He has since expressed remorse about the incident in a letter to the court, where he said he realized the books would “affect the general public.”

The creators of the sheep and wolves books were five members of the General Union of Hong Kong Speech Therapists. They were sentenced to 19 months in prison in September 2022.

Since then, a group of self-described overseas educators have taken over the project and published three more titles that are available to purchase in the U.K. Digital copies are also available for download.

Hong Kong has seen its freedoms decline in recent years as Beijing has tightened control over the city, following the imposition of a sweeping national security law aimed at stamping out dissent.

The national security law, together with the sedition law, has been used to arrest activists and outspoken pro-democracy figures.

Governments in the West have criticized the law as a dismantling of Hong Kong’s political freedoms and civil society. Chinese and Hong Kong authorities say the law is necessary to maintain stability in the city, which experienced months of anti-government protests in 2019.