PRAGUE- Czech state-owned hard coal mining group OKD will shut all its mining operations for six weeks from Friday as it battles an outbreak of coronavirus infections, it said on Thursday.

The mines, in the country's east near the Polish border, have been the Czech Republic's main hot spot of new cases in the past weeks.

OKD's decision means three deep mines will be shut in addition to the first location where the outbreak started and was shut on May 22.

News agency CTK reported that blanket testing of 3,403 employees at OKD's two CSM mines showed 704 positive cases, with no or mild symptoms. OKD did not immediately respond to a request for comment.

OKD supplies the northeastern Czech industrial region, near the borders with Poland and Slovakia, with 4 million tonnes of coking and thermal coal per year.

After weeks of country mostly reporting fewer than 100 cases a day, positive results spiked as high as 305 on June 28, before falling back to 92 on Wednesday.

The region of Karvina, where OKD's operations are based, was the worst-affected in the country in the past weeks.

Karvina had 270 cases per 100,000 people over the past seven days compared to less than 10 in the majority of the country.

The government, which has relaxed most restrictions on public life, maintained making facemasks obligatory inside shops and offices and on public transport in the most affected region, and banned public events there for over 100 people.

(Reporting by Robert Muller and Jason Hovet Writing by Jan Lopatka; editing by David Evans) ((jason.hovet@thomsonreuters.com; +420 234 721 613;))