SOME 83 people have now tested positive for COVID-19 at the Malaga Red Cross Centre.
There are understood to be 79 users of the centre who have contracted the virus, while the rest of those infected are staff.
The Malaga Red Cross Reception, Emergency and Referral Centre is located on Avenida de Jose Ortega y Gasset.
All exits and entrances to the premises have been sealed off and Policia Nacional officers and staff in hazmat suits are on-guard.
It comes after 100 people at the centre were isolated on Tuesday.
Everyone who has come into contact with an infected person is to receive a PCR test.
Early estimates have suggested that for every infected person, four PCR tests are needed for those who they came into contact with.
Most of those infected are young migrants, who were rescued by boat as they tried to cross the Mediterranean, according to Diario Sur.
It is understood that on Sunday a Red Cross worker was hospitalised with coronavirus symptoms.
The NGO reported that the member of staff had recently returned from the Canary Islands.
Those people the person came into contact with, including passengers on the plane they returned on, have been traced for testing.
Another person at the Red Cross Centre tested positive on Monday, with nine confirmed cases on Tuesday and a further six yesterday.
A source close to the outbreak told Diario Sur: “We are prepared to deal with the outbreaks.”
It comes as other coronavirus outbreaks were reported around Spain, including at military barracks in Cadiz.