The risk level related to the Omicron variant remains very high, the WHO said late Tuesday, with the numbers of new Covid-19 cases hitting another record high last week.

"Over 21 million new cases were reported, representing the highest number of weekly cases recorded since the beginning of the pandemic," the World Health Organization said in its weekly epidemiological coronavirus update.

The UN health agency said the number of new infections increased by five percent in the week to Sunday -- compared to the 20 percent rise registered the week before.

The WHO said, of the available data, Omicron accounted for 89.1 percent of the cases. Delta -- previously the world's dominant variant -- now makes up 10.7 percent.

Nearly 50,000 new deaths were also reported, it added -- a similar figure to the week before.