The World Health Organization's top official in Europe urged governments to prepare for a "significant surge" in coronavirus cases across the continent due to the Omicron variant, which is already dominant in several countries.

 "We can see another storm coming," WHO Europe regional director Dr Hans Kluge said at a press conference in Vienna on Tuesday evening. "Within weeks, Omicron will dominate in more countries of the region, pushing already stretched health systems further to the brink."

Omicron has been detected in at least 38 of the WHO European region's 53 members, Kluge added, noting that it is already the dominant variant in the United Kingdom, Denmark and Portugal.

Last week, 27,000 people died from coronavirus in the region and an additional 2.6 million cases were reported, Kluge said. Although these cases include all variants, not just Omicron, he noted this figure is 40% higher than during the same period last year.

"The sheer volume of new Covid-19 infections could lead to more hospitalisations and widespread disruption to health systems and other critical services," he said.

Thus far, Kluge said 89% of those with confirmed Omicron infections in Europe reported symptoms common with other coronavirus variants, including cough, sore throat, fever. The variant has mostly been spread by young people in their 20s and 30s in the region, he added.

Although much remains unknown about Omicron, Kluge said it appears to be more infectious than previous variants, leading to "previously unseen transmission rates" in countries with a significant number of Omicron cases. In those countries, cases of the variant are doubling every 1.5 to 3 days.

Omicron has forced countries across the world to impose new curbs days before Christmas, but a South African study offered a glimmer of hope about the new variant's firepower, reports Reuters.

Governments made urgent pleas for citizens to vaccinate as Omicron emerges as the dominant variant, upending reopening plans that many had hoped would herald the start of a post-pandemic era and unnerving financial markets.

According to WHO data, the Omicron variant has been confirmed in 106 countries.

Germany, Scotland, Ireland, the Netherlands and South Korea have reimposed partial or full lockdowns or other social distancing measures in recent days.

Austria, Belgium, the Czech Republic and Spain were among European countries due to consider new curbs yesterday.

Over 13 million people were ordered to stay home in the Chinese city of Xi'an, which imposed a strict lockdown yesterday and dramatically tightened travel controls to fight a growing Covid-19 outbreak, reports AFP.

However, a new South African study suggested reduced risk of hospitalisation in people infected with Omicron compared with Delta, although the authors said some of the reduction was likely due to high population immunity.

France said it could soon have around 100,000 new Covid-19 cases a day, up from around 70,000 currently as the country battles a fifth wave of the epidemic.

In India, the Delhi government yesterday banned all gatherings to celebrate Christmas and New Year amid surging Omicron cases.

President Joe Biden on Tuesday told Americans the country was "prepared" to fight Omicron, as Israel -- which pioneered the use of Covid vaccine boosters -- announced fourth shots for those over 60 and health workers.

The UK government yesterday announced that it is buying millions of doses of new Covid treatment pills as the Omicron variant takes hold, while cutting the isolation period for positive cases.

The government said it has signed deals to buy 4.25 million courses of two new antiviral drugs: Pfizer's ritonavir and US rival Merck/MSD's molnupiravir, which will be available early next year.