Tens of thousands of protesters paralysed central Hong Kong on Wednesday, blocking major roads in a defiant show of strength against government plans to allow extraditions to China.

Black-clad demonstrators, most of them young people and students, surrounded government offices, bringing traffic to a standstill as they called on authorities to scrap the Beijing-backed plan.

Rows of riot police were far outnumbered by protesters -- many of whom wore face masks, helmets or goggles -- just hours ahead of a scheduled debate in the city's legislature.

By late morning, with crowds continuing to swell, officials in the Legislative Council (Legco) said they would delay the second reading of the bill "to a later date".

It might be the most low-tech item at a Shanghai consumer electronics fair, but a bash-able Donald Trump is eliciting perhaps the most physical reaction from visitors amid his tech-and-tariff war with China.

A kiosk at the centre of the Consumer Electronics Show Asia (CES Asia) bills itself as a "stress-relief" station where you can smash a life-sized bobble-head likeness of the US president with a hammer.

The not-for-sale prototype serves as a proxy for more oblique Trump-bashing heard at the annual tech fair.

"It would be better if I could use my hands and feet. I think the hammer isn't satisfying enough," attendee Wang Dongyue, 31, said after sending the presidential noggin lurching back and forth.

A new policy by President Donald Trump is a shocking example of why it is imperative for America to confront its racist history, a progressive talk show host explained on Tuesday.

The explanation came after Time magazine headlined, "Trump Administration to Hold Migrant Children at Base That Served as WWII Japanese Internment Camp."

Jess McIntosh, the co-host of the SiriusXM show "Signal Boost" put the news in historical context.