HONG KONG • Activist Joshua Wong was yesterday jailed for the second time for his role in 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 judgment.

"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.

The court denied both accused bail, but defence lawyers pushed for the judge to reconsider his decision and were granted a further hearing yesterday afternoon. "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 Basic Law.

Ahead of the hearing, Joshua Wong said he had "no regrets" about his involvement. "They can lock up our bodies, but they can't lock up our minds."

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.

The city has been governed under a "one country, two systems" deal since 1997, when Britain handed the territory back to China. The pact allows citizens rights unseen on the mainland, including freedom of speech and a partially directly elected legislature, as well as an independent judiciary - but there are concerns those liberties are being eroded.

Joshua Wong was jailed for six months in August on unlawful assembly charges for involvement in the storming of a fenced-off government forecourt in 2014, which sparked the wider rallies.

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

Their appeal is being considered by Hong Kong's top court.

AGENCE FRANCE-PRESSE