A large Canary Islands hotel was locked down for coronavirus tests on Tuesday after a guest and his wife were found to be infected, as Spain also reported its first three cases of the disease on the mainland.
Catalan regional health authorities said a 36-year old Italian woman, a Barcelona resident, had tested positive after a recent trip to the north of Italy. Twenty-five people who came into contact with her will be quarantined at home for two weeks.
Shortly afterwards, authorities in Valencia and Madrid confirmed two more cases.
However, Spain's health minister, Salvador Illa, played down the severity of the outbreak, emphasizing that all cases have been imported from abroad and there has not yet been any domestic transmission of the infection.
The four-star H10 Costa Adeje Palace hotel in Tenerife went into lockdown after an Italian doctor on holiday on the island tested positive for the virus on Monday. His wife tested positive on Tuesday, the regional government said.
Two more Italians who had travelled to Tenerife with the couple were diagnosed with the infection, local authorites said in the early hours of Wednesday.
The couple had been moved to a hospital isolation ward, and other hotel guests and staff would be tested for the virus, a process that will take some days, health authorities said.
Guests will remain there until the results of a second test on the doctor are determined and, depending on that outcome, "appropriate health measures will be taken", a Spanish government spokeswoman said.
The hotel has hundreds of rooms, several restaurants and swimming pools, and is located 50 metres (55 yards) from the beach.
More than 700 guests spanning 25 nationalities, as well as staff members, are stuck in the hotel, Canaries regional government leader Angel Victor Torres said.
On its Facebook page, the hotel said it planned a carnival party on Thursday evening. Its management declined to comment on Tuesday.
Christopher Betts, an English guest from Leicestershire, said by phone from his room that there were police cars stationed at all entrances.
"We're told we're in quarantine... The hotel seems to be acting normally, except that we cannot go out," he said, adding that guests had been allowed to have breakfast in the restaurant.
Medical staff took the guests' temperature with digital thermometers and provided them with masks but did not perform any other tests, Betts said.
Tens of thousands are expected this week in the Canary Islands for carnival festivities.
Spain's health ministry advises against travelling to newly designated at-risk zones, including China, northern Italy and Iran, but has held off on more drastic measures such as a travel ban.
Before Monday, Spain had identified two coronavirus cases - a German tourist in La Gomera, another Canary Island, and a British man in Majorca.