Italy on Saturday reported 793 new coronavirus deaths, a one-day record that saw its toll shoot up to 4,825 -- 38.3 percent of the world's total.
The number of COVID-19 infections rose by 6,557 to 53,578, another record.
The total number of fatalities in the northern Lombardy regions around Milan surpassed 3,000. It accounts for nearly two-thirds of Italy's fatalities.
Italy has reported 1,420 deaths since Friday, a grim figure that suggests the pandemic is breaking through the government's various containment and social distancing measures.
The Mediterranean nation of 60 million has been under an effective lockdown since March 12, when public gatherings were banned and most stores shuttered.
Police were out in force across the streets of Rome on Saturday, checking documents and fining those outside without a valid reason, such as buying groceries.
Joggers were asked to run around the block of their houses, parks and beaches were closed, and the government in Rome prepared to extend school and other closures into the summer months.
But the outbreak keeps gathering pace in the new global epicentre of a virus that was first reported in December in China and has since transformed the world, straining health care systems, upending lives for millions and pummelling stock markets globally.
The figures released Saturday showed deaths still largely contained to Italy's richer north, whose world-class healthcare system is creaking but still not breaking.
But it is much better that what is available in the poorer south, whose regions have registered a few dozen deaths each -- and which the government in Rome is watching closely.
The Lazio region that includes Rome has recorded a total of 50 deaths and 1,190 infections.