The Czech Republic has suffered just 355 COVID-19 deaths, far fewer than in Western neighbors, but infections have resurged in the past three weeks, mostly concentrated in the industrial Moravia-Silesia region bordering Poland and Slovakia.
The area, which includes the city of Ostrava, is home to around 11 percent of the country's 10.7 million population.
Since lifting a strict nationwide lockdown imposed in March, the authorities have pledged to avoid future countrywide measures and instead respond to local outbreaks regionally.
The central European country has seen more than 100 new cases in seven out of the past 10 days, with a large portion from the northeast following an outbreak in the state-owned OKD coal mines.
Health Minister Adam Vojtech told a televised news briefing that the OKD outbreak was under control but new hotspots of infections appeared in several companies and among cross-border commuters, and hospitals were reporting more patient admissions.
"We have signals that...there are new cases of quite serious cases of patients diagnosed 7-10 days ago," Vojtech said. "Better be more careful now than try catch a speeding train later."
Under the new measures, public events attended by over 100 people were banned in the region, and cross-border workers have to present a negative swab test for the novel coronavirus every two weeks.
Visitors to hospitals and social care homes will have to wear respirators. Face masks will be compulsory indoors and on public transport, and bars and restaurants must close between 11 p.m. and 8 a.m.
The country had reported 13,612 total infections as of Thursday, with active cases creeping up to 4,617, near the high of 4,737 on April 11.