The World Health Organization (WHO) warned on Thursday that COVID-19 has been experiencing a resurgence, driven by a spike in cases from Europe.

WHO Director-General Dr. Tedros Adhanom Ghebreyesus said the rise in European cases is serious enough to be offsetting a fall in cases in other parts of the world. He added that this news should be a reminder that the pandemic is still not over, and precautions were still needed before a return to normalcy occurs.

“The global number of reported cases and deaths from Covid-19 is now increasing for the first time in two months, driven by an ongoing rise in Europe that outweighs declines in other regions,” said Dr. Ghebreyesus.

On Thursday, Russia experienced its highest day of new COVID-19 infections with 40,096 cases and a record 1,159 deaths. Just days earlier, President Vladimir Putin ordered a weeklong lockdown in the capital city of Moscow from Oct. 30 to Nov. 7, a move Russian officials have been loathe to repeat after first shutting down last year.

On Oct. 26, Ukraine was faced with a new record of COVID-19 deaths after its health ministry announced 734 deaths on that day alone. Like Russia, Ukraine is struggling to get more of its population vaccinated despite widespread skepticism over COVID-19 vaccines.

In the U.K., which boasts a very high vaccination rate and is implementing a booster shot campaign, officials warned that it could see new lockdown restrictions enacted if case numbers keep going up.

According to The New York Times' COVID-19 Vaccination Tracker, Europe has a 59% vaccination rate, the third-highest by region in the world.

Officials around the world have warned the winter season could prove challenging because it coincides with holiday traveling and flu season. It is possible to catch both diseases and it can be difficult to diagnose because of similarities in their symptoms.