Slovenia has formally declared an epidemic of the novel coronavirus amid a major surge in infections.
From Monday, a 30-day period allows the government to impose further restrictions to combat the outbreak.
Among these measures, professional examinations for health professionals and health care associates will not be conducted until further notice.
The government has also prohibited gatherings of more than six people and restricted the movement of citizens between 21:00 and 06:00.
Slovenia had already tightened face mask rules and restricted bars and restaurants, while most schoolchildren and university students have moved from classroom to online teaching.
In May, Slovenia was the first European country to declare the end of the epidemic after the spring wave.
But on Sunday, the nation reported 537 new cases of COVID-19, with 289 hospitalisations.
Prime Minister Janez Jansa said late on Sunday that people's health comes first and has urged citizens to act responsibly.
"Slovenians are still among the least affected EU countries [sic], but the situation is dangerously worsening," Jansa said in a press conference.
"Together with the rest of Europe, we are forced to take measures to control the spread of the virus, to protect health and lives."
"We still have a demanding cold period of the pandemic ahead of us, which requires effective action from all of us and above all a high level of responsibility and solidarity."