International hub has been shaken by 4 months of massive pro-democracy protests

The Hong Kong Squash Open has become the latest international sports event to be called off because of the unprecedented political unrest gripping the city.

The international hub has been shaken by four months of massive pro-democracy protests which have seen increasingly violent clashes between hardcore demonstrators and the police, as well as regular disruptions to transport.

A string of high-profile entertainment and sports events have been cancelled as a result, and Hong Kong's premier squash event, scheduled for December, became the latest casualty on Tuesday.

"Hong Kong Squash has decided, after careful consideration and extensive discussions with our key stakeholders, to postpone the 2019 Everbright Sun Hung Kai Hong Kong Squash Open... to next year," organisers said in a statement.

The annual Hong Kong Squash Open is one of the Professional Squash Association's world tour platinum events. It was last cancelled in 2003 during the SARS outbreak.

The wave of protests in Hong Kong 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 believe these are under threat from an increasingly assertive Beijing.

Street battles between riot police and small groups of protesters -- whose vandalism has targeted companies they consider to be pro-Beijing -- have become a weekly occurrence, hammering the already struggling economy, spooking tourists and undermining Hong Kong's reputation for stability.

The crisis has already forced the cancellation of the WTA Hong Kong Open tennis tournament and the postponement of a football friendly at home against Malaysia.

Several high-profile entertainment events -- from pop concerts and stand-up comedy shows to award-winning musicals -- have been scrapped as well.

Organisers of the mixed martial arts event HK4 also announced on Wednesday a postponement to March next year, citing safety concerns during the ongoing protests.