Spain on Monday started to reopen some businesses to save its struggling economy, as most of its lockdown restrictions remained in place, leading to concerns of a resurgence in COVID-19 infections.

The easing of restrictions has been applied to sectors in which people are unable to work remotely, such as construction and manufacturing. Police will hand out face masks at metro and train stations while reminding those returning to work of social distancing rules.

Meanwhile, the number of confirmed cases in Spain had grown to 169,496 on Monday, while deaths from the virus rose by 517 to 17,489, according to health authorities.

Spanish Prime Minister Pedro Sanchez stressed on Sunday that despite the daily continued decrease in new confirmed cases, the country is "not in a phase of de-escalation".

The relaxation of curbs has sparked concerns about a possible resurgence of the virus. Quim Torra, the leader of the Catalan region, insisted that the complete lockdown should not be lifted yet, saying lifting confinement measures "will lead to an increase of transmissions and a collapse of Catalonia's health system".

The virus had infected around 840,000 people across Europe by Sunday, according to the World Health Organization.

Deaths in France totaled 14,393 on Sunday, representing a one-day increase of 561.

The French aircraft carrier Charles de Gaulle returned to its base in the southern port of Toulon on Sunday after some 50 members of its crew and some aboard an escort frigate contracted the virus.

The French Defense Ministry said the entire crew of some 1,700 sailors would be tested and confined for 14 days in various military quarters. The same thing will be done for air crews aboard the vessel and those on the frigate.

Possible loose in curbs

In Germany, total infections had risen by 2,537 to 123,016, data from the Robert Koch Institute for infectious diseases showed on Monday. The reported death toll has risen by 126 to 2,799.

Also on Monday, Chancellor Angela Merkel and the premiers of Germany's 16 states got recommendations from the German National Academy of Sciences that the chancellor had said would weigh heavily in consideration for a possible loosening in movement and social distancing rules in place since around mid-March.

Italy on Sunday reported its lowest number of deaths, in three weeks, and the overall number of hospitalizations and patients requiring intensive care are trending downwards.

The pandemic had claimed 19,899 lives as of Sunday in Italy and infected 156,363 people, according to the Civil Protection Department.

In Russia, the mayor of Moscow Sergei Sobyanin warned that the outbreak is "getting worse", and announced the tightening of a lockdown in the Russian capital.

In a statement on his blog, Sobyanin announced that the city would gradually introduce a system of passes from Monday to monitor and regulate residents' movements during the partial lockdown.

Russia on Monday reported 2,558 new cases, a record daily rise, taking its tally to 18,328. Russia's coronavirus crisis response center said that 148 people diagnosed with the virus had died so far, an overnight rise of 18.

Xinhua and agencies contributed to this story.