The new strain of novel coronavirus, known as VOC-202012/01, has already been detected in eight European countries, WHO Regional Director for Europe Hans Kluge said.
"8 countries in the WHO_Europe region have now identified the new Covid19 variant VOC-202012/01," Kluge wrote in a Twitter post on Friday. "The variant also seems to be spreading among younger age groups unlike previous strains. Vigilance is important while research is ongoing to define its impact."
The official called for strengthening the existing protective measures, such as social distancing, wearing face masks and staying in core support bubbles.
On December 14, Britain's Secretary of State for Health and Social Care, Matt Hancock, said British scientists had identified a new coronavirus strain that might be to blame for high infection rates in southeastern England.
Prime Minister Boris Johnson told an urgent news conference on December 19 that according to the current findings the new strain might be 70% more contagious.
He added that British experts had not yet found any proof that the mutated virus was fraught with a greater risk of lethal outcome. Some countries, including Russia, have paused air links with Britain.