HONG KONG (Reuters) - Hong Kong organizers of an exhibition by a dissident Chinese-Australian cartoonist, a persistent thorn in the side of leaders in Beijing, canceled the event in the Chinese-ruled city on Friday given what they said were threats by China.

The exhibition by Badiucao was to have been his first international solo event. His work highlights themes including rights violations and abuse of power under Chinese Communist Party rule and he often satirizes President Xi Jinping.

“We are sorry to announce that the exhibition ‘Gongle’, by Chinese artist Badiucao, has been canceled out of safety concerns,” wrote the organizers, Hong Kong Free Press, Amnesty International and Reporters Without Borders, in a statement.

“The decision follows threats made by the Chinese authorities relating to the artist. Whilst the organizers value freedom of expression, the safety of our partners remains a major concern.”

The statement did not specify the threats. China’s representative Liaison Office in Hong Kong could not be reached for comment.

Hong Kong, a former British colony, returned to Chinese rule in 1997 under a “one country, two systems” principle, with the guarantee of a high degree of autonomy and freedoms, including freedom of expression, not enjoyed elsewhere in China.

But those freedoms have come under threat, pro-democracy activists say, with increased meddling by Beijing.

Badiucao was due to give a question and answer session at the opening alongside members of the Russian anti-Kremlin Pussy Riot punk band, as well as Hong Kong’s young democracy leader Joshua Wong.

Badiucao, considered one of the most prominent Chinese political cartoonists, gave no immediate response when contacted by email.

Amnesty International, one of the co-organizers of the exhibition, expressed concern.

“The threat Badiucao faces exemplifies how much overseas Chinese dissidents need to consider when they do their work,” said Amnesty China researcher Patrick Poon.

“It’s particularly worrying that it happens here in Hong Kong as the space for freedom of expression is eroding further this year,” Poon added.

Last month, Hong Kong authorities refused to renew a work visa for the Asia news editor of the Financial Times, soon after he hosted a talk by an independence activist at the city’s Foreign Correspondents’ Club (FCC).

“The incident might make other dissidents and artists rethink whether it’s safe for them to do their work in Hong Kong as they may also face similar situation in future,” Poon added.

Tom Grundy, the editor of Hong Kong Free Press, declined to give specifics as to the nature of the threats.