Residents of Spanish nursing homes have been found abandoned or dead in their beds as the country's coronavirus outbreak worsens, according to the nation's Defence Minister.

Key points: Spain is the second hardest-hit country in Europe after Italy

Spain is the second hardest-hit country in Europe after Italy Madrid is struggling to cope, with the highest number of cases

Madrid is struggling to cope, with the highest number of cases City authorities have used an ice rink as a makeshift morgue

The Spanish military has been brought in to help disinfect areas, including nursing homes, as the disease spreads in one of Europe's worst-hit countries.

"The army, during certain visits, found some older people completely abandoned, sometimes even dead in their beds," Defence Minister Margarita Robles told broadcaster Telecinco, according to the BBC.

She did not say what had caused the deaths.

The state prosecutor has opened an investigation into these fatalities.

Spanish health system on 'verge of collapse'

People who are aged 70 or older are most at risk. ( AP: Alvaro Barrientos )

The Health Ministry reported around 6,600 new cases and 500 deaths overnight. With nearly 40,000 cases and 2,696 deaths, Spain is Europe's worst-hit country after Italy.

Around 14 per cent of all infections are among health workers, which health emergency chief Fernando Simon attributed to the limited availability of protective equipment and several early clusters of the virus occurring in hospitals.

He also warned pressure on intensive-care units would continue after transmission of the virus among the general population had peaked.

Echoing his concerns, nursing union SATSE called for test kits and for drastic measures to help prop up Madrid's hospitals, which it said were on "the verge of collapse".

Spain's capital Madrid is struggling with the number of cases and its municipal funeral home said it would stop collecting bodies due to a shortage of equipment. Private funeral homes will still be operating.

Authorities in the Spanish capital on Monday agreed to transform the Palacio de Hielo mall, home to an Olympic-sized ice rink, into a morgue.

This Olympic-sized ice rink has been turned into a morgue in Madrid. ( Reuters: Juan Medina )

Soldiers were also deployed to Barcelona to help build a temporary homeless shelter at the city's Fira event centre.

The shelter, to be managed by the Red Cross, will allow up to 1,000 homeless people to isolate themselves in hygienic conditions, Barcelona's Mayor Ada Colau said.

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'What's killing people is the system'

Anger has been vented at Spain's private healthcare system amid the crisis. ( AP: Joan Mateu )

In the southern region of Andalusia, the mayor of a small town pleaded for help after reporting 38 of 42 residents at the local nursing home had tested positive for the virus, along with 60 per cent of staff.

"The virus doesn't kill people ... what's killing people is the system," Rafael Aguilera, mayor of Alcala del Valle told a news conference.

"We need oxygen, ambulances and hospitals," he said in a video posted on the town's Facebook page.

"A person died in our arms because we couldn't get hold of oxygen."

Deputy Prime Minister Carmen Calvo, who was born in 1957, was hospitalised over the weekend with a respiratory infection, the Government said. She is now awaiting coronavirus test results.

Two other ministers and the wife of Prime Minister Pedro Sanchez have tested positive for the virus over the past weeks.

Economy Minister Nadia Calvino said a nationwide lockdown, which has kept most Spaniards confined to their homes, was beginning to take a heavy toll on the economy.

"Economic activity, which was dynamic until February slowed significantly last week," she said, adding that the food, electricity and telecoms industries had continued to function normally.

Reuters/ABC