A Hong Kong student protester pleaded not guilty Friday to multiple criminal charges over a demonstration against a pro-Beijing figure, a day after the conviction of an "Umbrella Revolution" leader was blasted by rights activists.

The court cases come with feelings running high in the city over fears that Beijing is tightening its grip.

Billy Fung, former president of Hong Kong University's student union, faces a raft of charges over a protest at the university in January where students stormed a council meeting.

Supporters gathered outside the court to support Fung Friday, a day after teenage protest leader Joshua Wong and two other prominent student activists were convicted for a protest that sparked major pro-democracy rallies in Hong Kong, known as the "Umbrella Revolution".

That prosecution was slammed by rights group Amnesty International, which said the "vague charges" against Wong, Alex Chow and Nathan Law "smacked of political payback".

Speaking outside the court Friday, Fung said he worried other students could be targeted, after pleading not guilty to four charges -- criminal intimidation, disorderly conduct in a public place, criminal damage and attempted forcible entry.

The charges all relate to the student siege of the meeting in January in protest at the appointment of pro-Beijing Arthur Li to a senior administrative role.

Around 200 students surrounded an HKU building and refused to let both Li, who is council chairman, and the vice-chancellor of the university leave the meeting, according to reports at the time. They said Li "forced" their hand due to his unwillingness to speak with them.

Fung, now 22, was accused of shouting: "Don't let him go! Don't let Arthur Li go! Kill him, kill him!" according to a court charge sheet.

He was released on a cash bail of HK$10,000 ($1,300) and will appear in court again in September for a pre-trial review.

The appointment of Li was made by Hong Kong's unpopular leader Leung Chun-ying -- chancellor of all the city's universities -- and comes after months of controversy and protests over what some see as politically motivated decisions at the prestigious university.

It also tapped in to wider concerns that Beijing interference is affecting academic freedom and freedom of expression in the city.

The former British colony was handed back to China in 1997 under a deal that guaranteed the retention of its civil liberties and capitalist system for 50 years.