Thousands from Hong Kong’s LGBT community showed up at an annual pride rally on Saturday after police banned organisers’ application for a march for the first time since the parade was held in 2008.

At Edinburgh Place in Central, a smaller crowd turned up for this year’s carnival-like event, with the theme “Equal Justice, Equal Rights”. The gathering calls for equal treatment and better protection for sexual minorities, including legislation on sexual orientation-based discrimination.

Organisers said more than 6,500 people participated in the rally, but tensions from the ongoing anti-government movement and the anti-mask law contributed to a drop in attendance as those wishing to hide their identities would be deterred. Police put the turnout at 850.

On Thursday, police rejected the Hong Kong Pride Parade organising committee’s application for a march from Victoria Park to Edinburgh Place “in the interests of public safety and public order”, only approving a rally. Earlier, organisers had estimated the number of participants this year to drop by half from 12,000 at last year’s march.

Many in colourful outfits showed up on Saturday, carrying rainbow flags as before, but some were also masked and dressed in black – the signature look of anti-government protesters.

Mo, a Form Six student from the LGBT community, wore a black T-shirt and a black mask to the rally in defiance of the anti-mask law to show support for protesters’ five demands, as some of his schoolmates were arrested over the past few months during demonstrations.

The 17-year-old said he was a frontline protester who had helped built roadblocks last week and extinguish tear gas canisters in clashes with police. He said Saturday’s rally was mostly peaceful and it was a “pity” that police rejected the march.

“Every year, the pride parade is held. Police had only rejected this year’s march two days before despite an application being filed much earlier ... I believe when there is no police presence, everything will be peaceful,” he said, adding that he had participated in the pride parade for the past two years.

But Brian (not his real name), a lawyer in his 50s from Britain who has lived in Hong Kong for more than 20 years, said police’s decision to ban a march was “understandable” although it was “disappointing” because it could have built up better momentum for the event.

“[It was based on] safety, [including] worries about whether it would get hijacked for other purposes. I can understand that ... but I’m not going to blame one side or another,” he said.

Kwok, a mother in her 30s who joined the rally for the first time with her husband and 7-year-old daughter, said she felt freedom of expression in the city had been shrinking amid increasing numbers of rallies and marches being rejected by police, so she came to show support and “connect” with the LGBT community.

Ricky Chu Man-kin, chairman of the Equal Opportunities Commission, who attended Saturday’s rally wearing a rainbow-coloured wristband, said the watchdog would be stepping up the process of getting the proposal for the sexual orientation discrimination ordinance passed into legislation “very soon”.

Some details of legal provisions would be drafted on less controversial areas such as employment and educational rights, as well as the equal use of public services and facilities, which would then be put into consultation.

“Talks of the legislation have lasted for 24 years, we are trying to take a step forward now and see what the results will be,” Chu said. “I can foresee the process would be lengthy and might take up a lot of time, but I’m still optimistic.”

Diplomats from at least seven consulates also came to show support as openly gay figures including lawmaker Raymond Chan Chi-chuen were also present at the rally. Participants chanted protest slogans such as “there are no rioters, only tyranny” throughout the rally.