HONG KONG - Thousands took to the streets of Hong Kong on Saturday (June 18) afternoon, calling for freedom for the city.

"Hong Kong has a bottom line" and "We want our freedom", chanted the protesters in Cantonese as they marched from Causeway Bay to China Liaison Office in the western side of Hong Kong island.

Organisers said the march was organised to show support for Mr Lam Wing Kee, one of five booksellers who disappeared last year only to resurface on the mainland this year.

On Thursday, Mr Lam, 61, revealed details of his eight-month ordeal, including how his associate Lee Bo had told him that he was kidnapped from Hong Kong.

However, Mr Lee refuted Mr Lam's claims in a Facebook post the following day.

"If what Mr Lam said is true then we need to do something about it. It can happen again," said lawmaker Leung Kwok Hung, who was among the thousands who marched down approximately 6km route under the scorching sun.

Mr Leung was referring to China's apparent violation of the "One Country, Two Systems" framework, and how the personal safety of the Hong Kong people had been compromised.