Unemployment claims in the U.S. rose to 6.6 million last week from an unrevised 3.3 million the previous week, the Labor Department reported Thursday.

The figures far exceeded the median estimate of 3.50 million in a Reuters survey of economists. Estimates in the survey were as high as 5.25 million.

The government's weekly report, the most timely data on the economy's health, offered the clearest evidence yet that the longest employment boom in the U.S. history probably ended in March.

This is against the backdrop of the ongoing COVID-19 pandemic that has heavily hit business activities and people's daily life in the country. U.S. President Donald Trump warned late Tuesday that maintaining social distancing guidelines for the next 30 days would be a "matter of life and death." 

More than 80 percent of Americans are under some form of lockdown, up from less than 50 percent a couple of weeks ago, leaving state employment offices overwhelmed by an avalanche of applications.

The outbreak has spurred an unprecedented surge in Americans seeking government assistance. They have already outstripped applications for unemployment benefits that peaked at 665,000 during the 2007-2009 recession, during which 8.7 million jobs were lost.

Economists say the country should brace for jobless claims to continue escalating, partly citing generous provisions of a historic 2.2 trillion U.S. dollars fiscal package signed by President Donald Trump last Friday and the federal government's easing of requirements for workers to seek benefits.

As a result, self-employed and gig-workers who previously were unable to claim unemployment benefits are now eligible. In addition, the unemployed will get up to 600 U.S. dollars per week for up to four months, which is equivalent to 15 U.S. dollars per hour for a 40-hour workweek. By comparison, the government-mandated minimum wage is about 7.25 U.S. dollars per hour and the average jobless benefits payment was roughly 385 U.S. dollars per person per month at the start of this year.

Last week's claims data has no bearing on the closely watched employment report for March, which is scheduled for release on Friday. For the latter, the government surveyed businesses and households in the middle of the month, when just a handful of states were enforcing "stay-at-home" or "shelter-in-place" orders.

It is, however, a preview of the carnage that awaits. Retailers, including Macy's, Kohl's Corp and Gap Inc, said on Monday they would furlough tens of thousands of employees, as they prepare to keep stores shut for longer.

"A rough look at the most affected industries suggests a potential payroll job loss of over 16 million jobs," said David Kelly, chief global strategist at JPMorgan Funds in New York. 

"The loss would be enough to boost the unemployment rate from roughly 3.5 percent to 12.5 percent, which would be its highest rate since the Great Depression."

(With input from Reuters)