Ambulances medical staff deliver a patient wearing protection masks at Cruces hospital, in Bilbao, northern Spain, Saturday, March 21, 2020. Image Credit: AP

Europe's four worst-hit countries reported declines in deaths caused by the coronavirus, and an Italian health official said his country's outbreak may be cresting.

Latest data from Spain, Italy, France and the U.K. suggest the containment measures that have idled millions of workers are having an effect, prompting political leaders to extend or tighten them to further stem the pandemic. The Italian region around Milan added restrictions after many residents defied the quarantine and ventured outside.

"It's the lockdown measures that are helping us," Silvio Brusaferro, head of Italy's public health institute, said in Rome on Sunday. They have led to a "significant slowdown in the spread" of the virus, he said.

With the number of confirmed infections worldwide at more than 1.2 million, Italy and Spain have the biggest death tolls. That means officials have to weigh any attempts to restart parts of the economy against the risk of reigniting the spread of the virus and worsening the human toll.

Italy reported 525 new deaths on Sunday, the lowest daily number in 2 1/2 weeks, Spain's toll declined for a third straight day and the U.K.'s was lower than the previous day's. France reported an additional 518 deaths, the fewest since last Tuesday.

Deaths linked to the coronavirus reached almost 16,000 in Italy, more than 12,000 in Spain, 8,000 in France and some 4,900 in the U.K. Italy has counted 128,948 infections, slightly fewer than Spain.

As Italy heads into its fifth week under lockdown, opposition leader Matteo Salvini called on the government to open churches for the Easter holiday.

However, Prime Minister Giuseppe Conte said on NBC's "Meet the Press" earlier Sunday he can't say when the lockdown will end.

The U.K. will tighten a nationwide lockdown if needed to halt the spread of virus, Health Secretary Matt Hancock said Sunday, as officials face demands to say how they will eventually lift restrictions. That could mean banning all outdoor exercise, he said.

Authorities in Italy's Lombardy and Tuscany regions warned residents to stay home for all but essential activities and to shield their faces with masks or other coverings if they must go out. Italian police have fined over 175,000 people for lockdown violations since March 11, according to the Interior Ministry.

Italy's measures to keep the country shut down have been extended through at least April 13. Conte is expected to announce revised rules and timelines by the end of next week, the Il Messaggero newspaper reported. In Spain, Prime Minister Pedro Sanchez on Saturday extended a national lockdown for two weeks until April 25.

While Finance Minister Roberto Gualtieri said Italy is preparing new measures to provide liquidity to companies, Conte renewed his call for joint euro-area debt issuance that's also drawn support from Spain's government

"As the Italian government, I invite all its European partners to approve a European recovery and reinvestment plan," he said on NBC. "It's an ambitious common plan to rebuild the European economy to be financed through European recovery bonds."

Queen's Speech

Queen Elizabeth II is due to address the U.K. later Sunday. "I hope in the years to come everyone will be able to take pride in how they responded to this challenge," she will say, according to the BBC. "And those who come after us will say that the Britons of this generation were as strong as any."

Prime Minister Boris Johnson is in "good spirits" as he remains in isolation with a temperature, according to Hancock, the health secretary.

Scotland's Chief Medical Officer, Catherine Calderwood, apologized after she visited her second home, leading to calls for her resignation. The BBC reported she received a police warning.