Stock markets and oil prices plunged Friday over fears of a new coronavirus variant that scientists warn could be more infectious than Delta and more resistant to vaccines, potentially dealing a heavy blow to the global economic recovery.

Haven investments the yen and Swiss franc rallied but the dollar floundered.

Share prices of airlines and tourism groups dived as countries put in new travel restrictions, while there were big losses also for energy groups.

"Stock markets fell sharply... as fears a new COVID variant will lead to fresh lockdowns, mobility restrictions and lower economic growth," noted Neil Wilson, chief market analyst at Markets.com.

Europe's main equity markets were down at least three percent in afternoon trading following sharp falls in Asia.

On Wall Street, the Dow slumped 2.5 percent in its shortened trading day following Thursday's Thanksgiving holiday.

U.S. crude oil prices tumbled 10 percent, with the main international contract down over nine percent.

"It's Black Friday today for the retailers, but it's 'Red Friday' right now for the stock market," said Patrick O'Hare at Briefing.com.

Justin Tang at United First Partners said that while the latest news was worrying, "the world has gone through this before" with the Delta variant, adding that governments were more adept at knowing how to deal with the situation.

"Mutations are expected and not something unknown," he said.

The World Health Organization cautioned against imposing new travel restrictions over the new COVID variant B.1.1.529.

It added that it would take "a few weeks" for researchers to understand the impact of the variant detected in South Africa.

Germany's BioNTech said it was studying how well the coronavirus vaccine it developed with U.S. drugs giant Pfizer protects against the new variant.

"We expect more data from the laboratory tests in two weeks at the latest. These data will provide more information about whether B.1.1.529 could be an escape variant that may require an adjustment of our vaccine if the variant spreads globally," a BioNTech spokesperson said.

(With input from agencies)