Hong Kong activist Joshua Wong was jailed for the second time on Wednesday for his role in mass pro-democracy protests as concern grows that prison terms for young campaigners are shutting down debate in the semi-autonomous city as Beijing increases control.

Wong, 21, who became the face of the 2014 Umbrella Movement, was handed a three-month sentence on a contempt charge for obstructing clearance of a major protest encampment, to which he had pleaded guilty.

He was already on bail pending an appeal over a six-month sentence for another protest-related offence.

Judge Andrew Chan described Wong's involvement in obstructing the clearance in 2014 as “deep and extensive” in his written judgement.

“He played a leading role on that day,” he added. “The only appropriate punishment for Mr Wong is immediate imprisonment.”

Fellow activist Raphael Wong was jailed for four months and 15 days over the same incident.

Chan denied both bail but defence lawyers pushed for him to reconsider his decision and were granted a further hearing on Wednesday afternoon.

Meanwhile both activists were taken into custody by security guards.

“Our determination to fight for democracy will not change!” Raphael Wong shouted as he was led away.

Fourteen other defendants including leading activist Lester Shum were given suspended sentences on contempt charges.

Campaigners fear that the raft of cases against activists and the jail terms handed down to democracy leaders are discouraging young people from expressing their views and exercising their right to peaceful protest.

Freedom of speech and demonstration is protected by the city's mini-constitution, the Basic Law.

'No regrets'

Ahead of the hearing, Joshua Wong, who became the teenage face of the Umbrella Movement, said he had “no regrets” about his involvement.

“They can lock up our bodies but they can't lock up our minds,” he told reporters.

Dozens of supporters gathered outside the High Court, chanting: “Civil disobedience, no fear!” and “I'm a Hong Konger, I want universal suffrage!”

They were countered by a small group of pro-Beijing protesters waving the national flag of China and supporting Hong Kong's department of justice. They displayed a banner calling the activists “mobsters” and saying they must “pay the price” in jail.

The Umbrella Movement was an unprecedented rebuke to Beijing as tens of thousands of protesters brought parts of the city to a standstill demanding fully free leadership elections to replace a system where the chief executive is selected by a pro-Beijing committee.

They failed to win concessions and since then leading activists have been charged over their involvement.

Beijing has been further incensed by the emergence of some activists calling for independence for Hong Kong since the failure of the Umbrella Movement to win reform.

Wong's party Demosisto wants self-determination for the city.

Hong Kong has been governed under a “one country, two systems” deal since 1997, when Britain handed the territory back to China.

The agreement allows citizens rights unseen on the mainland, including freedom of speech and a partially directly elected parliament, as well as an independent judiciary, but there are concerns those liberties are being eroded.

Wong was jailed for six months in August on unlawful assembly charges for involvement in the storming of a fenced-off government forecourt known as Civic Square in September 2014, which sparked the wider Umbrella Movement rallies.

Wong and fellow campaigners Nathan Law and Alex Chow were originally given non-custodial sentences by a lower court over that incident, but after the government's intervention, they were jailed by the Court of Appeal.

The government's move was seen as further evidence of Beijing's growing influence over Hong Kong.

Their appeal against their sentences is currently being considered by Hong Kong's top court.