Amazon, Facebook and Twitter are among the tech giants canceling their participation in the Consumer Electronics Show (CES) in Las Vegas in early January.

This comes amid growing concerns about the Omicron variant of COVID-19, which is said to be more transmissible than previous variants.

But other companies, including Google and self-drive unit Waymo, are still physically attending the event.

CES will run for four days from January 5, with strict health protocols.

Only fully vaccinated attendees are welcome to attend the event, and organizers recommend a COVID-19 test prior to departure for Las Vegas and another within 24 hours of entering one of the venues.

A digital event will coincide with the physical, giving online participants access to conference sessions, keynote speeches and networking.

CES is one of the most notable events in the tech industry, where companies showcase the latest gadgets and discuss trends, attracting nearly 200,000 visitors a year and taking place in a major US city.