Italy plans to restrict movement throughout the entire country, Prime Minister Giuseppe Conte said Monday, effectively locking down some 60 million people in an unprecedented move to contain the coronavirus.

The announcement came a day after Italy imposed similar restrictions on one-quarter of the country. The rapid acceleration shows that Italian policymakers have come to believe that hard-line measures are the best way to slow the virus's spread.

A new oil price war sparked by the coronavirus sent shock waves through financial markets, with the Dow Jones industrial average cratering more than 2,000 points, or roughly 7.8 percent. Stocks tumbled around the world as more countries implemented measures to contain the outbreak and the United States' tally of known infections passed 500.

Italy's decision, aimed at dramatically reducing travel within one of Europe's most connected countries, shows the once-unthinkable steps that a Western democracy is willing to take amid the threat of the accelerating virus.

The move indicates that Italian policymakers have come to believe that hard-line measures are the best way slow the virus.

Entering this past weekend, Italy had imposed relatively minor movement restrictions - applying to 11 small towns with a total of 50,000 people - near the epicenter of the country's outbreak. Then, early Sunday, Italy took its first drastic move against the virus, with Conte announcing a plan to lock down areas around the virus's epicenter in the north, with travel restrictions applying to 16 million people.

It is now cutting off its citizens, no matter where they live, from most kinds of travel, including to other countries and from one region to the other.

There is a sense in Italy that the country is facing its greatest emergency since World War II. In recent days, the number of people to fall ill has accelerated, with active cases reaching nearly 8,000. In less than three weeks, 463 people have died.

Conte said Monday that it was necessary to expand the restrictions.

"I'm about to take a measure that we can summarize with 'I'm staying home,' " he said in introducing the changes.

As part of the announcement, Conte said schools would be canceled until April 3.

"Our habits need to change," he said. "They need to change now."

Meanwhile, markets sank to stunning lows Monday, triggering a forced halt to trading after the Standard & Poor's 500 index sank 7% shortly after the open bell.

The New York Stock Exchange tripped the "circuit breaker" at a time of relentless volatility for global stocks. The Dow Jones industrial average cratered more than 2,000 points, or roughly 7.8%, to close at 23,955. The S&P 500 shed 7.6% and the Nasdaq tumbled 7.3%.

"The uncertain economic impact of coronavirus continues to grip markets, with stocks, commodities and interest rates all dropping sharply," Greg McBride, chief financial analyst at Bankrate.com, wrote in a commentary on Monday. "Markets hate uncertainty and there is a ton of it currently in play."

Moscow's refusal to cut its oil output by half a million barrels a day shattered the unusual three-year marriage of OPEC, led by the Saudis, and major non-OPEC producers, led by Russia, as oil producers scrambled to find a way to respond to weakening global demand resulting from the deepening crisis over the coronavirus. Saudi Arabia, angered by Moscow's position, said Sunday that it would open its spigots and drive down prices, making this oil price cycle the only one in nearly a century to combine weak demand with a global price war.

President Donald Trump took to Twitter, posting: "Good for the consumer, gasoline prices coming down!"

And: "Saudi Arabia and Russia are arguing over the price and flow of oil. That, and the Fake News, is the reason for the market drop!"

Around the U.S., public health officials in King County said that there were 33 new cases of covid-19 reported in the area around Seattle, including two deaths. A third person who had previously been reported ill also died Sunday, bringing the total coronavirus-related deaths in the region to 20 - with 19 of them linked directly to a nursing home in Kirkland.

The three new deaths reported Monday were a woman in her 70s, a woman in her 80s and a woman in her 90s, all of whom had been residents at Life Care Center, the nursing home that has been most seriously affected during the outbreak in Washington state. Public health officials said they are coordinating testing of all Life Care Center employees and prioritizing testing of employees who have symptoms consistent with covid-19. Life Care Center has tested all of its residents and is awaiting test results.

The number of confirmed reported cases in King County has risen to 116, according to county officials.

In New York, Gov. Andrew Cuomo said that the head of the Port Authority of New York and New Jersey, Rick Cotton, tested positive for the virus and was being placed under quarantine.

Cotton, executive director of the Port Authority of New York and New Jersey, "is going to be on quarantine. He'll be working from home," Cuomo said.

The governor praised Cotton's work at busy international transit hubs, including John F. Kennedy International Airport, during the coronavirus outbreak. The number of cases in New York has grown to more than 150.

The senior team that works closely with Cotton also will home-quarantine, Cuomo said.

In Washington, District of Columbia officials urged hundreds who attended Christ Church Georgetown on several recent days to self-quarantine because of their exposure to the church rector, the Rev. Timothy Cole, who is the first known coronavirus patient in the city.

In Oakland, California, passengers cheered as the coronavirus-stricken Grand Princess cruise ship pulled into port.

"Thank you!" shouted one passenger. Others waved at the dockworkers.

The ship docked two days after its scheduled arrival in San Francisco, and its 3,500 passengers and crew members are set to be evaluated upon arrival. The roughly 1,100 crew members will be quarantined on board. California passengers will be taken to military bases in the state for quarantining, while other U.S. residents will be taken to military bases in Texas and Georgia.

Officials said Friday that 21 of the 46 people tested on the ship came back positive for the coronavirus, indicating that the illness could be spreading on the ship. Nineteen of those who tested positive were part of the crew.

Also Monday, the U.S. Army said its top commander in Europe and several staffers may have been exposed to the novel coronavirus during a recent conference.

"He and others potentially affected are self-monitoring and working remotely to fulfill their command duties and responsibilities," the Army said in a statement.

Army health officials have notified all other personnel who were potentially exposed and are consulting with medical professionals and host governments in Europe.

"Our nation, our Army, our allies and potential adversaries should know that our Soldiers remain ready," the Army statement said.

Also Monday, Israel said it would mandate a two-week quarantine for anyone arriving on international flights, a sweeping expansion of restrictions that critics said were at least partly driven by fear of singling out U.S. travelers and angering President Trump.

Prime Minister Benjamin Netanyahu, in a video, said all visitors and Israeli residents arriving at Ben Gurion Airport over at least the next two weeks must to proceed to 14 days of isolation. Israel's Ministry of Health did not immediately explain how the restrictions would work, especially for nonresidents.

"This is a tough decision, but it is essential to maintain public health," Netanyahu said, "and public health precedes everything."

The new restrictions, which would be among the strictest in countries battling the outbreak, come as the number of confirmed coronavirus infections reached 42 across Israel.

Germany reported its first two deaths, just as health authorities warned the public to brace for more. Two people in the region of North Rhine-Westphalia died Monday, the regional health ministry said, one in the western city of Essen and another in the district of Heinsberg about 50 miles southwest. A spokesman said he couldn't provide further details on ages or whether they had underlying heath conditions. The first German national with coronavirus died Sunday in Egypt, but was reported to have already been sick when he arrived there.

In Italy, prison riots have broken out, leading to at least one reported instance in which 20 inmates managed to escape, in one of the first visible signs of social turmoil linked to the coronavirus outbreak, according to police and prison union officials, as well as Italian media reports.The riots, which began Saturday and continued to escalate on Monday, stem from restrictions that have been put in place against visitors to limit the spread of the coronavirus - chiefly the suspension of visiting hours and drastically reduced time out of cells.

Iran announced 43 new deaths from the coronavirus in the country, bringing the total number of fatalities to 237, with 7,161 cases confirmed, the Health Ministry said Monday.

Iran holds the bulk of those affected in the Middle East, with only a few hundred other cases confirmed elsewhere in the region.

The country also announced that it has temporarily released about 70,000 prisoners to curb the spread of the virus, Iran's English-language Press TV said. Prisoners will "continue to be furloughed as long as [this measure] does not interfere with the society's security," Chief Justice Ebrahim Raeisi was quoted as saying.

Canada reported its first death from the avirus, as public health officials urged Canadians to avoid all cruise ship travel and the number of cases in the country continued to climb.Bonnie Henry, the provincial health officer of British Columbia, told reporters that a male resident in his 80s at the Lynn Valley care home in North Vancouver had died Sunday night. He had several underlying conditions, she said.

This article was written by Adam Taylor, Rick Noack, James McAuley and Brittany Shammas, reporter for The Washington Post.