HONG KONG (REUTERS) - Hong Kong is bracing for a weekend of unrest, with pro-democracy protests likely to mount in the China-ruled territory ahead of the 70th anniversary of the founding of the People's Republic next Tuesday (Oct 1).

Thousands of people are expected to rally in the city centre on Saturday evening after the authorities granted a permit for a gathering at Tamar Park, next to the headquarters of Hong Kong's legislative council.

The Asian financial hub marks the fifth anniversary this weekend of the start of the "Umbrella" protests, a series of pro-democracy demonstrations in 2014 that failed to wrest concessions from Beijing.

Rallies are also expected on Sunday to mark Global Anti-Totalitarianism Day, with solidarity events planned in cities across the world, including Paris, Berlin, Taipei, New York, Kiev, and London.

But the biggest protests are likely to be on the Oct 1 national day, with protesters saying they plan to use the holiday to propel calls for greater democracy on the international stage and to embarrass political masters in Beijing.

Activists plan a mass rally from Victoria Park in the bustling Causeway Bay district to Chater Garden near government headquarters.

Official festivities have been scaled back, with the authorities keen to avoid embarrassing Beijing at a time when President Xi Jinping is seeking to project an image of national strength and unity.

Pro-Beijing rallies are also planned in the city, raising the prospect of clashes.

Hong Kong has been roiled by sometimes-violent demonstrations for months, with protesters blocking roads and vandalising metro stations, and riot police firing tear gas, pepper spray, and water cannon at crowds.

Sparked by a Bill - since withdrawn - that would have allowed the extradition of suspected criminals to mainland China, the protests have since expanded into a broader pro-democracy movement.

Crowds chanting anti-government slogans trapped Chief Executive Carrie Lam in a stadium for hours on Thursday night after she held her first dialogue with the people in a bid to quell the unrest.

At about 1.30am, after most of the protesters had left the area more than four hours after the talks had ended, Mrs Lam and her senior officials were finally able to leave the venue in a convoy under police guard.