Authorities in Madrid have advised residents in areas with a high level of coronavirus cases to stay at home as the Spanish health ministry reported more than 3000 new infections for the fourth day running.
The country logged 3650 coronavirus infections in the past 24 hours, bringing the cumulative total to 386,054.
With 1199 infections, Madrid accounted for nearly a third of the new cases.
The region's deputy health chief, Antonio Zapatero, urged people to avoid unnecessary trips and meetings, and said those in the worst-hit areas should stay at home, though he ruled out any mandatory confinement for now.
"Although we're worried, I don't think the situation merits targeted lockdowns," he told reporters.
After being criticised for failing to give details on when and how schools would re-open, Madrid's education department said a full return to face-to-face classes would not be possible in September.
Instead, students are likely to receive a mixture of in-person and online teaching.
"All teachers have a lot of uncertainty. There haven't been clear guidelines," said Rocio Penco Valenzuela, a teacher in Madrid.
"We have no idea (about how schools will re-open) and we are a bit scared."
A total of 28,838 people in Spain have been killed in the epidemic.
In an effort to stall a resurgence, the government has shut down night clubs, told restaurants to close at 1am and all but banned smoking in public.
Equality Minister Irene Montero earlier demanded regional leaders take steps to close down brothels, which have been linked to at least one cluster of infections.
During a briefing on Thursday, health emergency chief Fernando Simon bluntly warned that things were not going well but stressed that the spiralling caseload was not a country-wide phenomenon.
"At a national level we cannot say the virus is out of control, although in some areas perhaps it is," he said.