Hong Kong (AFP) - An anthem long embraced by Liverpool Football Club has become the latest battle line drawn between Hong Kong's pro-democracy protesters and the city's police.

Demonstrators have begun singing "You'll Never Walk Alone" and banners bearing the song's title have sprung up at protest sites in the southern Chinese city after a pro-government lawmaker used it to defend the police.

The chant is the most recent addition to a protest soundtrack that has included a rousing battle-cry from the hit musical "Les Miserables", and a local rock ballad from the 1990s.

Ugly clashes have broken out in recent days between police and demonstrators who have staged more than three weeks of rallies that have paralysed parts of the Asian financial hub.

During a meeting at the city's legislative body last Thursday discussing the police's handling of the demonstrations, prominent pro-Beijing legislator Tam Yiu-chung said officers should take heart from "You'll Never Walk Alone".

But Tam's comments caused a furore among local Liverpool fans who noted the song has long been synonymous with the club's fight against police fabrications following the 1989 Hillsborough disaster in which 96 fans died.

In the aftermath of the stadium crush, British police falsely blamed fans for the chaos, prompting a lengthy legal battle to clear the club's name. The fight largely ended in 2012 when an official government panel found police incompetence was primarily responsible.

More than 1,000 local fans penned their names to a two-page advert in the popular pro-democracy tabloid Apple Daily on Saturday condemning the use of the song to defend police.

- Newest rallying cry -

As a result, the anthem has since become the latest rallying cry for protesters who sang it en masse over the weekend during evening rallies.

"We don't agree that such a meaningful song should be used to encourage the behaviour of the Hong Kong police over the past few weeks," Anthony Shiu, a 19-year-old Liverpool fan and protester who helped organise the petition told AFP.

"(We) think that the lyrics of the song can remind us about how terrible it is when police abuse their power... both in Hillsborough and with this movement," he added.

Protesters have accused the police of using increasingly violent tactics following four nights of violence -- although tensions calmed overnight Sunday.

The police say they have had to adopt a more confrontational approach to fend off a radical core of protesters.

It is not the first time those advocating for the right to choose Hong Kong's next leader have appropriated songs to boost their movement.

A Cantonese version of "Do you hear the people sing?", from the musical "Les Miserables" which is set against the revolutionary backdrop of the Paris Uprising of 1832, became the de facto anthem early on in the mass rallies.

The lyrics have been specifically tailored for Hong Kong's democracy movement. "We should all carry the responsibility to defend our city," the song begins. "We have inborn rights and our own mind to make decisions."

But it is '90s ballad "Hoi Fut Tin Hung" (Under a Vast Sky) by local band Beyond that has become the most popular rallying anthem of the protesters.

During some of the largest rallies crowds have spontaneously chanted the ballad -- a mournful lament for a brighter future -- in their tens of thousands.

The chants swell for the end of the song's chorus as the crowds proclaim: "Still free and independent/Forever singing my own song out loud".