Some 4,500 police, Red Cross volunteers and security guards handed out masks at 1,500 locations across Spain

Workers in Spain's construction and manufacturing sectors cautiously returned to work Monday as the daily death toll resumed its downward trend and new infections fell to the lowest level in three weeks.

One of the worst-hit countries in the world, Spain saw the daily death rate fall for three consecutive days last week, only to rise again on Sunday.

But on Monday it fell again, with 517 deaths in 24 hours, putting the overall death toll at 17,489 with the number of cases now standing at 169,496.

Confirmed cases also rose by 3,477—the lowest daily figure since March 20—as Spain began reopening parts of its economy after a two-week "economic hibernation" period.

Although health chiefs say the outbreak in Spain has peaked, they have urged the population to keep observing a strict national lockdown imposed on March 14 to slow the spread of the virus.

The restrictions were further tightened on March 30 when all non-essential activities were frozen for two weeks—largely targeting the construction and manufacturing sectors.

But those restrictions were lifted on Monday in the nation of around 47 million people despite warnings from some quarters that lifting restrictions too soon could trigger a fresh outbreak.

Mask handouts

With workers heading back to their jobs, the government began a huge operation to distribute 10 million masks this week.

Some 4,500 police, Red Cross volunteers and security guards handed them out at 1,500 locations across the country, the interior ministry said.

At Madrid's Atocha station, commuters took the masks from officers at arm's length.

"It's amazing that the government is doing this because either you can't find them in shops or they're very expensive," said nurse Brenda Palacios, who took two of them.

As people headed back to work, the government began distributing 10 million masks

Masks have been hard to come by in recent weeks and some commuters said the handouts put them at ease during their trips to work.

"It's wonderful because it's so necessary and it helps those of us who have to use public transport," said office worker Jose Antonio Cruces.

"Most people (on public transport) don't have masks or gloves."

'We don't know who's infected'

Although public transport in much of Spain has been largely empty in recent weeks, the few commuters using it often do not have protective gear.

"I work in health care and we have them but very few of them, so I didn't have one to travel to and from work," said Maria Martinez.

For commuters, having a mask is essential as "we don't know who's infected or if we ourselves are asymptomatic," she said.

Figures released by the Madrid metro showed passenger traffic on Monday was up 24 percent compared with the same time last week.

Despite the partial easing of restrictions, Health Minister Salvador Illa stressed that "economic activity has restarted only in some very limited sectors", and that the generalised ban on people's movements needed to be strictly respected.

While some firms reopened on Monday, shops, bars, restaurants and other businesses considered nonessential remained closed.

Transport Minister Jose Luis Abalos said the level of people's confinement to their homes has been "very high".

"According to our data about 67 percent of people practically do not go outside at all," he told a news conference.