Hong Kong - Hong Kong's international Rugby Tens tournament in April next year - a curtain raiser to the city's famous Sevens - has been cancelled, the latest sporting event to fall victim to seething political unrest.

Organisers for the 10-a-side jamboree, part of a week-long rugby festival culminating in the Hong Kong Sevens from April 3-5, 2020, had been struggling to attract teams after six months of protests rocking the financial hub.

"Owing to the ongoing situation in Hong Kong, the tournament has, for the first time, had difficulty in attracting and securing firm commitments from enough overseas teams of sufficient quality," hosts Hong Kong Football Club said in a statement late Wednesday.

"We have made the decision not to host what would have been a diminished event in 2020."

The tournament has been held on the Wednesday and Thursday before the Hong Kong Sevens every year since 1986 and features teams packed with past and future stars of the game.

The Sevens, part of the World Rugby's global series, are scheduled for April 3-5 and organisers said they were determined the showpiece will go ahead.

Hong Kong has been upended by six months of massive democracy protests which have seen increasingly violent clashes between hardcore demonstrators and police, as well as regular transport disruptions.

A string of high-profile sports and entertainment events have been cancelled or postponed as a result, including pop concerts, stand-up comedy shows and award-winning musicals.

Golf postponed

Tennis's WTA Hong Kong Open, the Formula E Grand Prix and the Hong Kong Squash Open are among sporting events to have been cancelled.

The flagship Hong Kong Open golf tournament, won by world stars such as Rory McIlroy and Justin Rose in recent years, was postponed last month and rescheduled for January.

The wave of protests was sparked by opposition to a now-scrapped proposal to allow extraditions to mainland China, but have since morphed into a larger movement for democracy and police accountability.

The city enjoys unique rights under the terms of its handover to China by Britain in 1997, including freedom of expression and an independent judiciary. But many feel these are under threat from an increasingly assertive Beijing.

Street battles between riot police and small groups of protesters have become a weekly occurrence, hammering the already struggling economy, spooking tourists and undermining Hong Kong's reputation for stability.

The last three weeks have seen a rare lull in the violence and vandalism after pro-democracy parties won a landslide in local council elections.

But Beijing and city leader Carrie Lam have shown no sign they are willing to make further concession, leading to fears clashes could resume.