Chinese President Xi Jinping declared the opening of the Beijing Winter Games, triggering a burst of fireworks that marked the start of an Olympics whose preparations were beset by the Covid-19 pandemic and criticism over human rights in China.

Friday's ceremony in a partially-filled Bird's Nest stadium - the scene of Beijing's triumphant 2008 Summer Games launch - was filled with imagery of ice and snow, with Xi's declaration followed by red-suited "skaters" sliding across virtual ice.

Held on the first day of Spring by the Chinese calendar, it began with a performance by dancers waving glowing green stalks to convey the vitality of the season, followed by an explosion of white and green fireworks that spelled the word "Spring".

On a three-dimensional cube resembling a block of ice, lasers carved figures from each of the previous 23 Winter Games. The block was then "broken" by ice hockey players, enabling the Olympic rings to emerge, all in white.

That was followed by the traditional "parade of nations", with each of the 91 delegations preceded by a women carrying a placard in the shape of a snowflake resembling a Chinese knot.

In keeping with Olympic tradition, the parade was led into the stadium by Greece with the rest ordered by stroke number in the first character of their Chinese name, which meant Turkey was second, followed by Malta, with host China going last and drawing roars from the stadium crowd.

Team Ireland were led out by flag bearers Elsa Desmond and Brendan Newby

Russian President Vladimir Putin, the highest profile foreign leader present for the Games, could be seen in the stadium without a mask. However, the athletes from his country were unable to carry its flag due to doping violations, marching instead under the standard of the Russian Olympic Committee.

Friday's ceremony began shortly after Xi and Bach entered the iconic Bird's Nest stadium.

Bach hailed China's arrival as a "winter sport country" as a "new era for global winter sport".

Torchbearers hold the Olympic flame in the middle of a giant snowflake

Soon after the start, the Chinese flag was passed among 56 people representing China's different ethnic groups before it was raised and the national anthem performed.

Directed by Zhang Yimou, reprising his role from Beijing's 2008 Summer Games triumph, the event featured 3,000 performers on a stage comprised of 11,600 square metres of high-definition LED screen resembling an ice surface.

All of the performers were ordinary people from Beijing and nearby Hebei province, with "the Story of a Snowflake" its central thread.

With temperatures of about -4C at the start - not enough to daunt the shirtless flagbearer from American Samoa - the show was set to be about half as long as the four-hour marathon that opened the 2008 Games, also at the Bird's Nest.

The crowd itself was pared down, with organisers deciding last month not to sell tickets to Olympic events to curtail the spread of Covid-19. A "closed loop" separates competitors and other personnel from the Chinese public throughout the Olympics.

The official start of the Games will come as a relief to organisers navigating the extreme complexity of staging them during a pandemic while adhering to China's zero-Covid policy.

Organisers also hope it dampens a steady drumbeat of criticism from activists and governments over China's human rights record in its far western Xinjiang region and elsewhere - criticism that China rejects.