Thousands of protesters filled the city streets of Hong Kong this past Sunday after the mysterious disappearances of different publishers and booksellers. The citizens involved in the disappearances have been connected to books that criticize Chinese authorities.

According to CNN, the Hong Kong Alliance in support of Patriotic Democratic Movement of China organized the protests. About the Chinese government, Democratic party lawmaker Albert Ho said in an interview with The Guardian, “They owe us answers.”

Ho continued to claim the citizens are entitled to information about the booksellers’ statuses.

According to CNN, the latest citizen to go missing was Lee Bo, who disappeared from his warehouse last month. He worked for a company set to publish a book on the Chinese president Xi Jinping and his alleged love affairs. Bo is the fifth citizen to disappear under similar circumstances.

According to TheGuardian.com, protesters gather holding signs saying “Release Hong Kong Booksellers Now!” and “Against political persecution!” These protests have grown in popularity as the amount of people missing increase. The Chinese government has not yet commented on the disappearances.