Spain's health minister on Tuesday called on residents of Madrid to limit their movements and social contacts to the "essential" to put the brakes on a surge in Covid-19-19 infections, a day afer new restrictions came into effect in part of the region.

Spain is struggling to contain a second wave of the virus, which has already infected over 670,000 people and claimed over 30,000 lives, one of Europe's highest tolls. Madrid has become the epicentre of the contagion with a rate of infection of nearly 700 cases per 100,000 inhabitants in the last two weeks -- nearly three times the national average.

"I would recommend residents of Madrid to limit to the maximum their movements, that they scrupulously respect the measures dictated by the health authorities in the region and minimise their movements to what is essential and their contacts to those closest to them," Health Minister Salvador Illa said during an interview with radio Cadena Ser.

His comments come a day after a partial lockdown came into effect on some 850,000 people in the Madrid region -- mostly in densely populated, low-income districts in the south -- who account for 13 percent of the region's population of 6.6 million but 24 percent of virus infections.

The restrictions which came into force on Monday prevent people from entering or leaving the affected areas, except for work, education or to seek medical care but they can move around freely withing their zone.

The affected areas have all counted more than Covid-19 cases per 100,000 inhabitants -- around five times the national average, which in itself is the highest in the European Union.

The regional government of Madrid, which is responsible for health care, also reduced the maximum size of permitted social gatherings across the entire region from ten to six.

Many epidemiologists have expressed doubts about the effectiveness of Madrid's new measures but Illa said he believed they could help control the spread of the virus and that it would not be necessary to declare a state of emergency in the region, a step which would allow the government to confine people to their homes.

Since the central government ended its state of emergency on June 21, lifting all national lockdown restrictions, responsibility for public healthcare and managing the pandemic has been left in the hands of Spain's 17 autonomous regions.