Chinese dissident Liao Yiwu and former Hong Kong bookseller Lam Wing-kee on Thursday urged European countries to step up support for Hong Kong's pro-democracy demonstrators, as they joined an umbrella vigil at the Frankfurt book fair.
"We need to work together with European countries, we must do everything we can to preserve freedom of expression and democracy in Hong Kong," Liao told a crowd of some 200 people, many of whom held up black umbrellas.
"Europe isn't clear about what's going on. That's because of what the communist government is doing," said the Berlin-based writer, who was jailed for a poem about the 1989 Tiananmen Square protests and whose works are banned in China.
Umbrellas are the symbol of the anti-government protest movement that has rocked the semi-autonomous territory in recent months, posing the biggest challenge to China's rule since the city's handover from Britain in 1997.
The demonstrations were initially sparked by opposition to a now-scrapped proposal to allow extraditions to mainland China.
But they have since morphed into a larger movement for democracy and police accountability, and have turned increasingly violent.
China has accused "external forces" of fuelling unrest in the Asian financial hub and has seized on supportive comments by Western politicians to back its claims.
- 'Free Gui Minhai' -
Former bookseller Lam, who fled to Taiwan earlier this year for fear of possible extradition to China, also took to the stage in the German city of Frankfurt to plead for stronger action.
He welcomed a draft US law that would link Hong Kong's special trading status to annual reviews of its respect for civil rights and the rule of law.
"I hope the EU, the UK government and others can bring in similar laws," Lam said, calling for sanctions on government officials and police officers who commit rights violations.
"By placing restrictions on them, by not allowing them to travel into the country or preventing them from investing. That would help Hong Kongers a lot."
Lam was one of five Hong Kong publishers selling gossip-filled tomes on China's leaders who vanished at the end of 2015, before resurfacing in Chinese custody.
He and three others were released in 2016, but Gui Minhai, a Chinese-born Swedish citizen, remains in detention in unclear circumstances.
Organisers of the Frankfurt vigil called for his release and read out a letter by his daughter Angela who has led efforts to keep her father's case in the media.
"It's been four very long years and I'm exhausted," she wrote from Sweden, accusing the Chinese government of a harassment campaign against her.
"More often than not quitting seems very easy," she said, thanking supporters for "always showing up for my father".
"Here's to him being with us next year."
The Frankfurt book fair, the world's largest, has staged a series of events since 2016 under the banner #FreeGuiMinhai, while Germany itself has emerged as a country of refuge for a number of Chinese and Hong Kong dissidents.
German Foreign Minister Heiko Maas last month drew Beijing's ire when he met prominent Hong Kong activist Joshua Wong.
On her last trip to Beijing, Chancellor Angela Merkel stressed that the rights and freedoms of the people of Hong Kong "must be guaranteed".