Hundreds of thousands of non-essential employees in Spain have returned to work as European countries grapple with the question of when lockdown restrictions should be eased amid fears of a renewed spike in the coronavirus pandemic.

Police handed workers masks at transport hubs in the capital, Madrid, on Monday and businesses in the construction and manufacturing sectors tentatively reopened, after the government relaxed some lockdown measures put in place two weeks ago that confined most people to their homes.

The controversial return to work for an estimated 300,000 non-essential staff got off to a slow start. Monday is a public holiday in much of the country, including some of the most populous regions such as Catalonia and Valencia. Few commuters were visible at Madrid’s usually bustling Atocha railway station.

The prime minister, Pedro Sánchez, has insisted the country remains firmly in lockdown despite the easing of some restrictions. Shops, bars and public houses will remain closed until at least 26 April. The health ministry has called on those returning to work to stagger arrival times and to wear masks where physical distancing is not possible.

Regional leaders have criticised the move amid fears that the hard-fought public health gains of recent days may be lost. Spain’s overnight death toll from the virus fell to 517 on Monday from 619 on Sunday, bringing the total death toll to 17,489, the health ministry said.

It was the smallest proportional daily increase since tracking began. Overall cases rose to 169,496 from 166,019. The health minister, Salvador Illa, said the epidemic had passed its peak. The challenge now was to consolidate the second stage of the struggle against the virus and to reduce new infections, he said.

The trend across Europe appears to show a similar modest flattening of infection and death rates. Italy reported 566 deaths on Monday, 135 more than on Sunday. Almost half of the deaths – 280 – were registered in Lombardy, the northern region worst affected by the virus.

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The civil protection authority said the number of people who are currently infected rose by 1,363 (1.3%) to 103,616, in a further sign that the curve is flattening. The number of intensive care beds in use continues to decline, as does the number of people hospitalised for the virus.

European countries face the same dilemma as Spain: whether to ease some lockdown restrictions in order to salvage their battered economies, or to persevere with draconian measures until the decline in cases is conclusively achieved.

Italy’s government has set up a taskforce led by the former chief executive of Vodafone Vittorio Colao to navigate the country’s exit from the coronavirus lockdown. The team of 17 will be responsible for devising a plan as part of “phase two” of the emergency.

It includes Enrico Giovannini, a former labour minister and professor at Tor Vergata University of Rome, as well as other economists, businesspeople, lawyers, sociologists and psychologists. Italy’s lockdown is in place until 4 May, after which the country is expected to gradually reopen.

Germany’s chancellor, Angela Merkel, will decide on Wednesday whether to extend restrictions imposed in mid-March. They are due to expire on Sunday. The latest figures from the Robert Koch public health institute show the rate of infection slowing, with 2,537 new cases on Monday, taking the tally in Germany to 123,016.

The country’s Academy of Sciences Leopoldina has recommended a gradual relaxing of measures. It said schools should reopen as soon as possible, starting with primary and middle schools, followed by shops and restaurants. All government officials should return to work, it said.

Austria is to allow small shops to reopen from Tuesday, and larger ones from 1 May. All restaurants and hotels are due to resume business from mid-May. Denmark will reopen schools and day care centres from Wednesday, although restrictions on public gatherings and on bars and restaurants remain.

The head of the World Health Organization, Tedros Adhanom Ghebreyesus, urged caution over moves by countries to lift lockdown conditions. He said much was still unknown about the behaviour of the virus, and emphasised that case finding, testing and isolating was still crucial to controlling the outbreak.

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He said: “We know that in some countries, Covid-19 cases are doubling every three to four days. However, while Covid-19 accelerates very fast, it decelerates much more slowly. In other words, the way down is much slower than the way up.”

Sánchez said Spain’s decision to reboot some sectors of the economy was taken following consultations with a committee of scientific experts. Any further winding – down would depend on gains made against the virus, he stressed. So far 500,000 people have been fined an average of €300 (£260) for breaking lockdown.

In other developments:

Russia introduced a new digital permit system for anyone seeking to travel around Moscow during its lockdown. However, the website offering Muscovites a QR-code went offline just hours after launch. Moscow’s mayor blamed an attack by foreign bots.

China reported 108 new cases, 98 of which were imported from overseas, its highest figure since early March. The country where the disease first emerged has largely brought its domestic outbreak under control, but it faces a fresh battle against imported infections, mostly involving Chinese nationals returning home.

Indonesia announced 316 new cases of the coronavirus, bringing the total number of infections to 4,557, according to data provided by a health ministry official, Achmad Yurianto. Yurianto said there were also 26 new coronavirus-related deaths, taking the total number of fatalities to 399.

Japan said it saw no reason at the moment to extend its state of emergency beyond Tokyo and a handful of other cities. The central government declared a state of emergency last week, giving legal authority to governors in Tokyo and six other potential virus hotspot prefectures to ask people to stay home and businesses to close.