German authorities in North Rhine-Westphalia are bringing back local lockdown measures after a coronavirus outbreak linked to a meatpacking plant.
More than 1,500 employees of the Tönnies plant have tested positive.
State premier Armin Laschet said the "preventative measures" in Gütersloh district, home to about 360,000 people, would last until 30 June.
It is the first such move since Germany began lifting its lockdown restrictions nationwide in May.
The country has been praised for its response to the crisis, but there are fears infections are rising again.
What's happening in Gütersloh?
Mr Laschet described the outbreak linked to the Tönnies meatpacking plant, south-west of the city of Gütersloh, as the "biggest infection incident" in the country.
"We have decided that further measures are necessary," he told reporters.
People are not barred from leaving the area, but Mr Laschet appealed for local residents "not to travel to other districts".
Bars, museums, cinemas and gyms must all close, and restaurants can only serve meals to take away. Stricter social distancing measures are back in force, meaning people can only meet one person from outside their own household in public. Schools and nurseries for 50,000 children have been closed.
There is also a mandatory quarantine in place for all employees of the affected plant. Three police units have been deployed to enforce the measures, accompanied by aid workers.
Authorities have put up metal fencing around residential buildings where workers live and are distributing food to more than 7,000 employees.
Mr Laschet said it was important that the workers in quarantine are treated humanely. Only 24 residents of the district who do not work at the plant have so far tested positive for the virus, he added.
Bulgarian, Polish and Romanian consular staff have all visited the region and translators are on hand to speak to migrant workers.
Mr Laschet criticised the Tönnies Group on Tuesday for their response, telling reporters their willingness to co-operate "could have been greater".
All operations at the site were suspended last Wednesday. A spokesman for the Tönnies Group apologised for the outbreak.
Local authorities have the power to enforce different measures in their areas. Regulations differ from region to region.
This is not the only localised outbreak in Germany. A tower block has been placed under quarantine in the central German city of Göttingen, and police were sent to maintain order on Saturday after residents tried to get out.
Officials said those inside attacked officers with fireworks, bottles and metal bars. Most though have been complying with the quarantine.