An exhibition by a dissident Chinese-Australian cartoonist in Hong Kong has been cancelled by its organisers over what they said were threats from China.
Badiucao's work focuses on rights abuses and satirises President Xi Jinping.
His show was part of events examining free speech in Hong Kong since the 2014 pro-democracy "umbrella" protests.
The cancellation comes as pro-democracy activists say Hong Kong's freedoms are being eroded by Beijing.
In a statement, Free Expression Week organisers Hong Kong Free Press, Amnesty International and Reporters Without Borders said Badiucao's first solo show "Gongle" had been cancelled over "safety concerns".
"The decision follows threats made by the Chinese authorities relating to the artist. Whilst the organisers value freedom of expression, the safety of our partners remains a major concern," they said.
Badiucao had also been due to take part in a question and answer session at the opening alongside pro-democracy leader Joshua Wong and members of Russia's feminist protest band Pussy Riot.
The event organisers did not specify what the threats against the cartoonist were. Badiucao has also not commented. China's Liaison Office in Hong Kong could not be reached for comment.
Amnesty International's China researcher Patrick Poon said the threat "exemplifies how much overseas Chinese dissidents need to consider when they do their work".
He said it might also make other dissidents wary of working in Hong Kong in the future.
"It's particularly worrying that it happens here in Hong Kong as the space for freedom of expression is eroding further this year," he added.
In a post on Instagram, Badiucao described Hong Kong as "the city of resistance and hope".
Some of his cartoons portray President Xi as the children's book character Winnie the Pooh, after Chinese internet users said there was a resemblance.
Hong Kong, a former British colony, was handed back to China in 1997 on condition it would retain "a high degree of autonomy, except in foreign and defence affairs" for 50 years.
China operates a "one country, two system" agreement, with freedom of speech and press freedom among the key liberties that set Hong Kong apart from the mainland.
In 2014 protests calling for fully democratic elections for Hong Kong's leadership paralysed parts of central Hong Kong for several weeks.
The sit-in became known as the "Umbrella movement" after protesters used umbrellas to shield themselves from tear gas fired by police.
Last month Hong Kong refused to renew a work visa for Victor Mallet, the Asia news editor of the Financial Times, sparking concerns from the UK government.
Mr Mallet is also vice-president of the city's Foreign Correspondents' Club (FCC), which upset local and Chinese authorities by hosting a separatist speaker in August.