Four Hong Kong pro-democracy activists accused of obstructing justice in a case dating back to 2014 have appeared in court.

The activists behind the so-called Umbrella Revolution of 2014 said on Tuesday that the case was "politically motivated".

Joshua Wong, Nathan Law, Albert Chan and Raphael Wong were protesting against Chinese interference in Hong Kong's electoral process before a vote for a new chief executive in 2017.

"All four defendants have denied the charge of obstruction, an offence that can carry sentence of up to two years in prison," Al Jazeera's Rob McBride reported from outside the court.

Q&A: The Hong Kong teenager who confronted China

"Their supporters came to the court chanting political slogans," he said.

Wong, 19, was the face of the 2014 movement that lasted 79 days to demand free elections for the Chinese-controlled city's top leader.

The movement caught the world's attention but did not result in any substantial change, as China wants to keep its control on the territory it inherited from the UK in 1997

In an interview with Al Jazeera last year, Wong said he was afraid to go to prison.

"I know that greater power will result in greater responsibility, and greater responsibility will result in a greater price. I need to pay the price. If I'm in prison, it's a chance to show what's really behind myself, to motivate me to fight for three or four years," he said in September.

Last year, Wong was attacked when he came out of a cinema after watching a film.

"Beijing would like to see tough sentences handed down but the court will be conscious of the potential backlash," Al Jazeera's McBride said.

"There is simmering political tension here ever since the Occupy Movement of two years ago. It doesn’t take much for that to spill over into violence on the street."