Residents of two tower blocks in western Germany have been put under quarantine after a woman was diagnosed with the infectious variant of Covid-19 identified in India, an official said on Tuesday.
Some of the 179 residents have since been tested for coronavirus, public health official Marcus Kowalczyk said.
Mr Kowalczyk said that sequencing the samples to establish if they had the Indian variant would take several days.
Authorities around Europe are on high alert for the variant, which caused devastation in India before establishing a foothold in Britain.
Infectious variants are a major threat to governments' ability to contain the pandemic.
"It started suddenly on Sunday," said Ute Nicole Gaertner, a resident of one of the buildings in Velbert, near Dusseldorf.
"Suddenly council officials were everywhere and then we were locked in.
"It's terrible. I have four children, a very disabled child who needs therapy. It's a bit difficult here at the moment."
The earlier spread of a variant first identified in Britain forced authorities in Germany to delay plans to soften lockdown rules this the year.
The number of confirmed coronavirus infections in Germany rose by 4,209 to 3,603,055, data from the Robert Koch Institute for infectious diseases showed on Tuesday.
The reported death toll rose by 221 to 86,381.
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