Democracy campaigners jailed in Hong Kong

Human rights groups say three jailed activists are "political prisoners" and their imprisonment marks a "disgusting milestone".

Three young democracy campaigners have been jailed in Hong Kong, in what human rights groups say is the territory's first political prosecution.

Joshua Wong, 20, Nathan Law, 24, and Alex Chow, 26, were led down from the dock to begin six to eight-month prison terms for their role in the 2014 Umbrella protest movement.

The sentence disqualifies them from running for Hong Kong's legislature for five years.

The three were convicted of "unlawful assembly" by a lower court last year.

Wong and Law were ordered to carry out community service, which they had already completed, and Chow was given a suspended three-week prison term - but prosecutors appealed for harsher sentences.

Prison terms had been widely expected, with hundreds of supporters crowding into the foyer to hug and applaud them as they walked into court.

"You can lock up our bodies but not our minds! We will not give up," Wong tweeted.

Law, who had been Hong Kong's youngest ever directly elected politician, before he was removed from office earlier this year over the manner in which he took his oath, appealed to their supporters to continue the campaign.

"When dozens of us political prisoners are in jail, could you, who are still free, fight for us on the streets?" he asked.

Chow has been close to completing his Masters degree, and hoped to begin his doctorate in the United States.

"Since Xi Jinping's rise to power, the Hong Kong government's ever-growing restrictions on civil and political rights put many young dissidents behind the bars," a statement released by their party, Demosisto, said.

"For the sake of Hong Kong's democracy, they can chain us, but they can never imprison our determination."

Another 13 activists were jailed earlier this week over their role in the Umbrella protests after a similar appeal by the Department of Justice.

"Hong Kong's first political prisoners - what a disgraceful, disgusting milestone," said Sophie Richardson, China director at Human Rights Watch, via Twitter, on Thursday.

Amnesty International said the "relentless and vindictive pursuit of student leaders using vague charges smacks of political payback by the authorities".

There is increasing concern among pro-democracy groups at the erosion of rights in the territory.

The rights were meant to be guaranteed for 50 years from the territory's handover from British rule, under what was known as the "one country, two systems" agreement.

"Joshua Wong, Nathan Law, Alex Chow, and other Umbrella Movement protesters are pro-democracy champions worthy of admiration, not criminals deserving jail time," former US presidential candidate Senator Marco Rubio said.

"Hong Kong's cherished autonomy is precipitously eroding. Beijing's heavy hand is on display for all to see as they attempt to crush the next generation of Hong Kong's pro-democracy movement."

But the territory's justice department said there was "absolutely no basis to imply any political motive" and the three had been convicted for "disorderly and intimidating behaviour".

As he was led from the dock, Wong raised one fist into the air.