Hong Kong police displayed a cuddly bear mascot and unveiled a new goose-step march Thursday as the financial hub held a "National Security Education Day", part of its push to instil patriotism in a city chafing under China's rule.

Beijing blanketed Hong Kong in a sweeping national security law last year in response to months of huge and often violent democracy protests that convulsed the international business hub.

Thursday's education day, the first since the security law's imposition last June, saw activities held across the city that burnished the security forces and outlined the threats China perceives it faces in Hong Kong.

At a morning ceremony attended by senior officials, Luo Huining, Beijing's top envoy in Hong Kong, gave a fiery speech vowing to "strike down hard resistance and regulate soft resistance", warning that China was ready to "teach a lesson" to any foreign power trying to use the city "as a chess piece".

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"For all deeds that endanger national security and Hong Kong's prosperity and stability, the central authorities will take action as necessary," he said.

In 2019, huge crowds hit the streets for seven straight months demanding democracy and greater police accountability in the worst unrest since the city's 1997 handover to China.

Beijing's authoritarian leaders have dismissed the movement, portraying it as an insidious "foreign plot" to destroy China.

They have since embarked on a crackdown against critics and rolled out an official campaign -- dubbed "staunch patriots governing Hong Kong" -- to root out disloyalty towards the Chinese Communist Party.

Across town on Thursday, Hong Kong's police college held an open day in which officers revealed a new goose-step march, the same style used by police and troops on the Chinese mainland.

The display was a symbolic break from Hong Kong's British colonial past and Chinese army officers helped train police in the new style.

Tactical units then held an "anti-terrorism drill" which included officers rappelling from a helicopter to shoot dead pretend armed militants and a hostage-taker.

Virtual reality prison guards

On the sidelines, guests wearing "I love police" t-shirts posed for selfies with a bear mascot dressed in tactical uniform.

Cuddly toy versions of the bear were also on sale for HK$400 ($52) alongside plastic toys of police officers holding tear gas warning flags.

Schools have been a major focus for authorities as they seek to incubate loyalty from an early age and national security day activities were held across classrooms featuring "games and puzzles".

Education authorities have already ordered children as young as six to be taught about the four new national security crimes -- subversion, secession, terrorism, and collusion with foreign forces.

The Correctional Services Department also held open days where guests could don a virtual reality headset to experience what it is like to be a prison guard.

More than 10,000 people were arrested during pro-democracy protests and more than 2,500 charged.

Over 100 people have also been arrested under the new security law, mostly pro-democracy politicians and opposition figures.