Spain’s daily coronavirus death toll rose to its highest in a week as authorities warned that a second wave of the outbreak was possible after a nationwide antibody survey showed about 5 per cent of the population had contracted the virus.

The number of fatalities caused by the disease reported each day rose to 217 up from 184 on the previous day, Reuters reports.

The reasons for the increase are unclear, head of health emergencies Fernando Simon said.

“We are now working with the region to identify the date of the deaths and evaluate whether these are new fatalities or if there was a delay in the update,” Simon said.