The grim toll of coronavirus deaths in Italy — the world’s worst-hit nation — surged past 4,000 as New York and other US states joined California in ordering a lockdown to try to bring the pandemic under control.

While new infections were being detected around the globe, the World Health Organization said the central Chinese city of Wuhan, where the pandemic began in December, offered a glimmer of “hope for the rest of the world”, with no fresh cases reported.

As Italy reeled from its worst single-day toll with more than 600 deaths, worldwide fatalities swept past 11,000, with the number of infected people topping 258,000.