A single coal mine in Poland's Upper Silesia region is behind a record spike in the country's confirmed coronavirus cases, the health ministry says.
Over the weekend 1,151 new infections were recorded nationally.
An outbreak among miners and their families at the Zofiowka colliery in southern Poland accounted for two-thirds of that figure.
The global number of deaths from coronavirus has now passed 400,000. There have been 6.9 million infections.
Poland introduced a strict lockdown early in March, and has avoided the comparatively large number of deaths seen in Western Europe.
In Poland, 1,157 people have died from Covid-19 and 26,561 have been infected but the stubborn persistence of cases in Upper Silesia mean the country has not passed its peak.
Most EU countries recorded fewer new cases than Poland on Sunday.