HONG KONG (AFP) - Crowds gathered Saturday (June 4) for Hong Kong's commemoration of the bloody Tiananmen Square crackdown but many young activists turned their backs on the candlelit vigil as calls grow for greater autonomy from China.

The vigil, which each year draws tens of thousands to the city's Victoria Park, has caused a widening rift in Hong Kong's pro-democracy camp between those who believe the victims of the crackdown should be remembered and those who see the event's message as increasingly irrelevant.

Semi-autonomous Hong Kong is the only location on Chinese soil to see a major commemoration to mark the military's brutal crushing of pro-democracy protests in central Beijing in 1989.

But young activists from the new "localist" movement say Hong Kong should push for its own autonomy, even independence, rather than the democratisation of the mainland, which is part of the vigil's main message.

Localism grew out of the failure of the 2014 student-led pro-democracy rallies to gain concessions from China on political reform for Hong Kong, and a growing number of student groups have now broken away from the event.

Students at a forum at Hong Kong University, one of several alternative events held to compete with the main vigil, said they felt little connection with the traditional commemoration.

"We're the new generation - it is more meaningful for us to do this. We have to stand against the Chinese regime, but we also have to think about Hong Kong's future," said student Raven Kwok, 20, among around 200 who had gathered for the forum.

The president of HKU's student union, Althea Suen, said the fight was now about democracy for Hong Kong. Building a democratic China was "not our responsibility", she said.

The Hong Kong Federation of Students - a founding member of the alliance that organises the vigil - also stayed away this year, saying the event had "lost touch" with Hong Kongers.

The pro-independence Hong Kong National Party added that, while young people still feel sorry for the students killed in 1989, "they don't share the same memory of Chinese identity with the older generation." Others were more acerbic in their criticism.

Shue Yan University student union likened the organisers of the vigil to "pimps and bawds who run a brothel after they got raped themselves" in a Facebook post. However, those filing in to Victoria Park on Saturday evening defended the vigil.

"This event is not perfect, but it still has meaning. I've been coming for many years," said Lily Wong, 21, a legal clerk.

Both Wong and her friend Cecilia Ng, a 19-year-old student, said vigil organisers should talk to new political groups about the shape of the event so that it was more representative.

Without it, the memory might disappear, they said. "I feel really sad about this, even though I wasn't born (then)," Ng told AFP. "Many of my classmates don't know or understand what happened." Eva Wong, 36, remembers her own teachers crying in front of pupils after the June 4 crackdown in 1989.

"Some day it might happen again if we don't fight it," said Wong.

Vigil organiser Richard Tsoi, from the Alliance in Support of Patriotic Democratic Movements of China, said if the event was axed, Tiananmen would be rendered a "non-issue" due to repression from Beijing.

Hundreds - by some estimates more than a thousand - died after the Communist Party sent tanks to crush demonstrations in the square in the heart of Beijing, where student-led protesters had staged a peaceful seven-week sit-in to demand democratic reforms.

The protests are branded a "counter-revolutionary rebellion" by Chinese authorities and many on the mainland remain unaware of the crackdown.

Tsoi hopes for a turnout of more than 100,000 people Saturday, similar to numbers in recent years.

Some student groups have backed the vigil saying the Tiananmen protests and crackdown helped politicise a new generation and have organised forums to explain its impact to Hong Kongers.

On the mainland, police detained several activists linked to commemoration events while "Tiananmen Mothers" - an association of parents who lost children during the violence - were surrounded by security forces as they visited the graves of their loved ones on Saturday. Tiananmen Square itself was also heavily policed.