Asia

Hong Kong protesters decry Beijing's detention of bookseller

  • Oscar Lai, a member of pro-democracy group Demosisto, throws a newspaper reporting Hong Kong bookseller Lam Wing-Kee into the Chinese central government's liaison office in Hong Kong, Friday, June 17, 2016. Lam, one of the five Hong Kong booksellers whose disappearances sparked international concern, said Thursday he spent months confined in a room under constant surveillance by mainland Chinese authorities, who interrogated him about his publishing company's authors and customers. (AP Photo/Kin Cheung)

    Oscar Lai, a member of pro-democracy group Demosisto, throws a newspaper reporting Hong Kong bookseller Lam Wing-Kee into the Chinese central government's liaison office in Hong Kong, Friday, June 17, 2016. Lam, one of the five Hong Kong booksellers whose disappearances sparked international concern, said Thursday he spent months confined in a room under constant surveillance by mainland Chinese authorities, who interrogated him about his publishing company's authors and customers. (AP Photo/Kin Cheung)  (The Associated Press)

  • From left, members of pro-democracy group Demosisto, Agnes Chow Ting, Joshua Wong and Oscar Lai, hold the placards and newspaper with picture of Hong Kong bookseller Lam Wing-Kee during a protest in Hong Kong, Friday, June 17, 2016 as they march to the Chinese central government's liaison office. One of the five Hong Kong booksellers whose disappearances sparked international concern said Thursday he spent months confined in a room under constant surveillance by mainland Chinese authorities, who interrogated him about his publishing company's authors and customers. (AP Photo/Kin Cheung)

    From left, members of pro-democracy group Demosisto, Agnes Chow Ting, Joshua Wong and Oscar Lai, hold the placards and newspaper with picture of Hong Kong bookseller Lam Wing-Kee during a protest in Hong Kong, Friday, June 17, 2016 as they march to the Chinese central government's liaison office. One of the five Hong Kong booksellers whose disappearances sparked international concern said Thursday he spent months confined in a room under constant surveillance by mainland Chinese authorities, who interrogated him about his publishing company's authors and customers. (AP Photo/Kin Cheung)  (The Associated Press)

  • Members of pro-democracy group Demosisto, Joshua Wong, left, and Oscar Lai, hold the placards and newspaper with picture of Hong Kong bookseller Lam Wing-Kee during a protest in Hong Kong, Friday, June 17, 2016, as they march to the Chinese central government's liaison office. One of the five Hong Kong booksellers whose disappearances sparked international concern said Thursday he spent months confined in a room under constant surveillance by mainland Chinese authorities, who interrogated him about his publishing company's authors and customers. (AP Photo/Kin Cheung)

    Members of pro-democracy group Demosisto, Joshua Wong, left, and Oscar Lai, hold the placards and newspaper with picture of Hong Kong bookseller Lam Wing-Kee during a protest in Hong Kong, Friday, June 17, 2016, as they march to the Chinese central government's liaison office. One of the five Hong Kong booksellers whose disappearances sparked international concern said Thursday he spent months confined in a room under constant surveillance by mainland Chinese authorities, who interrogated him about his publishing company's authors and customers. (AP Photo/Kin Cheung)  (The Associated Press)

Hong Kong pro-democracy groups are rallying against China's tightening grip on the semiautonomous city following electrifying revelations by a bookseller who spoke out about his months-long detention in the mainland.

Several dozen people marched Friday morning to Beijing's liaison office to vent their anger after Lam Wing-kee's testimony about his harrowing ordeal.

He's one of five people linked to a publisher specializing in salacious books on elite Chinese politics. They disappeared last year and later ended up in mainland police custody.

Lam said he was blindfolded, detained and interrogated for months by mainland authorities.

Protesters from the Demosisto political party tossed a newspaper, a book and a petition letter over the liaison office's fence.

An organizer said Lam "risked his life to tell the truth."