A Hong Kong court on Wednesday handed democracy activists Joshua Wong and Raphael Wong prison terms of three and four and a half months, respectively, for criminal contempt in relation to a pro-democracy demonstration in 2014.

The High Court also gave suspended sentences of 12 or 18 months to 14 others, some of whom such as Lester Shum were also fined between HK$10,000 (around US$1,280) and HK$15,000.

Both Wongs will file for appeal after the court denied their applications for stay of execution, according to Nathan Law, who like Joshua is a member of the political group Demosisto.

"We are very disappointed with the ruling," Law said after the court denied bail to the Wongs. "Using court injunctions to solve political issues is unprecedented."

He added that instead of prosecuting protestors, the government should bear its constitutional responsibility, while Beijing "should honor its promise of allowing Hong Kong universal suffrage."

The 16 activists had already been convicted of contempt of court for obstructing bailiffs who were ordered by the court to clear a site in Mong Kok district, one of several parts of the territory occupied by tens of thousands of protesters during the 79-day demonstration calling for a democratic leadership election.

High Court Judge Andrew Chan said in Wednesday's ruling that Joshua Wong's "involvement in obstructing the clearance operation was deep and extensive," adding that he played a leading role. "The only appropriate punishment for (Wong) will be one of immediate imprisonment."

On Raphael Wong, Chan said he "played a significant and active role in obstructing bailiffs" during the clearance operation and so gave him the longest prison term.

Joshua Wong said Wednesday he has no regrets.

"They can lock up our body, but they can't lock up our mind," Wong said. "Even if we need to face prison sentencing, we will still continue to fight for democracy for the future."

His three-month sentence would be served consecutively to a six-month term earlier meted out to him for unlawful assembly in relation to the same protest. He is currently free on bail appealing that ruling.

Before the hearing, Raphael Wong said the government has not responded to activists' demand for "real universal suffrage" in the territory's leadership election.

"Rather, they keep using the law as a tool to solve their political problems. Isn't that a contempt of court?" said the member of the radical political group League of Social Democrats.

Four others prosecuted for criminal contempt over the case were given a suspended sentence of one-month imprisonment last November.

The mass street protest, which was known as "Occupy Central," ended with more than 1,000 people being arrested but failed to press Beijing for a democratic reform plan.

According to the Basic Law, the mini-constitution in effect since Hong Kong's handover to China, Beijing promised to allow elections of the city's leader and legislators by universal suffrage as an "ultimate aim" under the "one country, two systems" arrangement.

In 2014, a package of electoral reforms endorsed by China would have allowed Hong Kong residents to directly vote for their next chief executive in the 2017 election, but only from a list of pre-approved, pro-Beijing candidates. It was rejected by the local legislature, with critics dismissing it as "fake universal suffrage."