Thousands of protesters marched through central Hong Kong Sunday, demanding the release of five missing booksellers who are feared to have been detained by authorities in mainland China.
The five are from Hong Kong's Mighty Current publishing house known for books critical of Beijing.
Their disappearance has fueled fears that freedoms in the semi-autonomous Chinese city are being eroded.
The US State Department and European Union have expressed concern.
The latest to vanish is Lee Bo, 65, last seen in Hong Kong on December 30.
Three others earlier went missing in southern China and one in Thailand.
In 2014 tens of thousands of protesters brought parts of Hong Kong to a standstill for more than two months after Beijing imposed restrictions on planned democratic elections for the city's next leader.