BERLIN (AP) — The World Health Organization says that the number of reported new COVID-19 cases worldwide decreased by nearly a quarter last week, continuing a decline since the end of March.

The Geneva-based U.N. health agency said in a weekly report that nearly 5.59 million cases were reported between April 11 and 17, 24% fewer than in the previous week. The number of newly reported deaths dropped 21% to 18,215.

WHO said new cases declined in every region, though only by 2% in the Americas. The report was dated late Wednesday and sent to journalists on Thursday.

The agency said that “these trends should be interpreted with caution as several countries are progressively changing their COVID-19 testing strategies, resulting in lower overall numbers of tests performed and consequently lower numbers of cases detected.”

The countries with the highest reported case numbers last week were South Korea with more than 972,000, France with over 827,000 and Germany with more than 769,000, WHO said. The highest numbers of new deaths were reported by the U.S., with 3,076, Russia with 1,784 and South Korea with 1,671.

In all, more than 502 million cases of COVID-19 and nearly 6.2 million deaths related to the coronavirus have been reported so far.