A Hong Kong student activist who became a face of a pro-democracy movement in the Chinese-ruled city has been deported from Thailand after being detained on arrival at the airport.
Joshua Wong, 19, was held in Bangkok where he had been invited to speak at two universities about Hong Kong's Umbrella Movement street protests and on setting up his political party, Demosisto.
"Demosisto has just been informed by the Hong Kong Immigration Department that ... Joshua Wong has boarded Hong Kong Airlines HX772 earlier from Bangkok, Thailand, en route back to Hong Kong." Demosisto said in a statement posted on its Facebook page.
His supporters have accused Beijing of being behind the move.
Al Jazeera's Adrian Brown, reporting from Beijing, said a senior official at the immigration office at Bangkok's airport had "responded to a request by China to blacklist" Wong.
"He was therefore denied entry into Thailand and deported," he said.
The Umbrella Movement protests in Hong Kong, the former British colony which returned to Chinese rule in 1997, brought the city to a standstill for three months and presented Communist Party rulers in Beijing with one of their biggest political challenges in decades.
Wong was given 80 hours of community service by a Hong Kong court in August on a charge of unlawful assembly for taking part in a sit-in at the height of the protests in the Asian financial centre.
Thailand has been ruled by a military junta since a 2014 coup which was widely condemned by the West. Since then, the generals running Thailand have forged closer ties with Beijing.
Wong said in a Facebook post on Tuesday night that he was concerned about his trip to Bangkok.
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"We all know Thailand is not politically stable... It is also clear that it is close to the Chinese Communist Party," he said.
Wong was denied entry by Malaysia in May 2015 when he was due to give a series of talks on democracy in China.
He had been invited to Thailand by Chulalongkorn University's Faculty of Political Science to speak on the 40th anniversary of a bloody crackdown by the Thai army on student protesters. Organisers said that he was detained at Bangkok's main airport on Wednesday morning.
Immigration officials confirmed to the Reuters news agency that Wong was prevented from entering Thailand and would be sent back to Hong Kong. Officials said they were under orders not to speak to the media about why Wong had been refused entry.
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Human Rights Watch condemned his detention.
"Thailand's arrest of Joshua Wong, a well-known pro-democracy activist in Hong Kong, sadly suggests that Bangkok is willing to do Beijing's bidding," Sophie Richardson, China director for Human Rights Watch, said in an email.
Demosisto, the political party that Wong heads in Hong Kong, also called for his release.
Thailand, Southeast Asia's second-biggest economy, is slowly recovering from the events of 2014, when months of street protests and the coup almost brought economic activity to a standstill.
Since then, the military has clamped down on dissent and banned political protests.