Those living in the affected areas of the capital - a total of 19 civil parishes that do not include downtown Lisbon - will be allowed to leave home only to buy essential goods such as food or medication, and to travel to and from work.

"The only effective way to control the pandemic is to stay home whenever possible, keep physical distance at all times and always maintain protection and hygiene standards," Prime Minister Antonio Costa told a news conference.

The measure will be in place from July 1 until July 14 and it will then be reviewed, according to a government document.

In the designated 19 areas, there will be a limit of five people for gatherings, compared to 10 in Greater Lisbon as a whole and 20 for the rest of the nation.

Thursday's announcement came after the government introduced restrictions on Tuesday that included an order for most commercial spaces in Greater Lisbon, excluding restaurants, to shut at 8 p.m. each day.

Overcrowded trains

There will be more police patrols to ensure people follow the rules, and those who fail to comply will be punished, Costa said.

Portugal, which has reported a total of 40,415 cases and 1,549 deaths from the coronavirus, has been hailed as a success story in the fight against the disease. It began lifting its lockdown on May 4.

But localized outbreaks in poorer neighborhoods and industrial hubs, as well as stemming from parties and raves along the coast, have kept cases increasing at a steady daily rate in the hundreds for the past month.

Images of overcrowded trains and buses to and from the city center have raised alarms, with many people blaming public transport for the new cases.