Hong Kong student leader Joshua Wong was back in court Friday over an anti-China protest, a day after he faced new charges related to a pro-democracy rally.

Wong, 18, has accused the authorities of "political prosecution" as they hit him with a raft of cases.

"The government and police have a political agenda," Wong told AFP at court Friday.

The charges he faces relate to various protests between June and November last year.

"I think it's quite unreasonable. They could have taken us to court last year... It's meaningless," he said.

Wong became the teenage face of the pro-democracy "Umbrella Movement" that gripped Hong Kong for more than two months at the end of 2014.

Protesters were calling for free elections of the semi-autonomous city's next leader, opposing a blueprint laid down by Beijing which would have meant candidates were vetted by a loyalist committee.

That reform package was voted down by legislators in June, in an unprecedented rebuke to Beijing.

Friday's hearing concerned a small anti-China protest last June -- ahead of the major rallies -- which saw dozens gather outside Beijing's representative office in Hong Kong.

They were opposing a "white paper" from China that asserted its control over the semi-autonomous city and a reproduction of the document was burned.

Wong, student leader Nathan Law, 22, and activists Raphael Wong and Albert Chan have been charged with obstructing police at the June incident.

All have pleaded "not guilty".

The case was adjourned Friday until October 26 when there will be a stay of proceedings hearing.

"They've known about this since the day of the arrests," said Wong's lawyer Michael Vidler.

"Why haven't they proceeded? We're saying it's politically motivated."

Wong and Law were also charged Thursday over a student protest in September which helped spark the widespread democracy rallies.

Wong faces further charges over a democracy rally last November, but said he was determined to keep campaigning.

"Sometimes because of the court, I can't go to school -- it really affects my daily life and my academic process," Wong told AFP on Friday.

"It's frustrating and tiring, but I still think it's worth paying the price."

Wong said his campaign group, Scholarism, would be announcing a new strategy in September.

It will coincide with the September 28 anniversary of the start of the democracy rallies -- the date when police fired tear gas at protesters, galvanising thousands more to come out in support of the movement.

Wong called for universal suffrage in the short-term and "self-determination" as a long-term goal after 2047, when the 50-year agreement to protect Hong Kong's way of life, which took effect when Britain handed the city back to China in 1997, comes to an end.

"I'm still optimistic... but of course it's hard for us to change the system in the next two or three years.

"We just hope to gather and strengthen civil society to fight for us in the future," Wong said.