Hunters, drones and helicopters with thermal cameras have been deployed to find a lioness believed to be on the loose around Kleinmachnow, near Berlin, the capital of Germany.
Authorities have warned people to avoid forests and urged parents to keep children indoors, according to Sky News.
More than 30 patrol cars were deployed after an emergency call was received around midnight.
Sky News said members of the public reported a wild animal running free in Richard-Strauss-Weg in Kleinmachnow and sent a video of the incident.
“The two gentlemen recorded a smartphone video and even experienced police officers had to confirm that it is probably a lioness,” police spokesman Daniel Kiep said.
Police used loudspeakers and emergency apps to warn people in the Kleinmachnow, Teltow and Stahnsdorf areas – who were also advised to keep pets inside.
Officials said riot police had also been deployed “to protect the population” and armoured vehicles were seen in the vicinity.
Local kindergartens will remain open but children are not being allowed out to play, according to a spokeswoman for the municipality.
Police said no zoos or circuses had reported missing an animal, raising the possibility it could be an escaped pet.
A lunchtime update from officials said the suspected lioness was still unaccounted for.
“We recommend that people shouldn’t leave the house to walk and especially not to go jogging in the forest,” said Michael Grubert, mayor of Kleinmachnow.
Another source said, “Two passersby spotted an animal chasing after another. One was a wild boar and the other appeared to be a big cat, a lion.
“The two men recorded a video on their phones and even experienced police officers had to confirm that we are probably dealing with a lion.”
He said the video of the big cat appeared genuine and the aim was to tranquilise the animal – only killing it if it poses a danger.
“Other reports in Standsdorf or Berlin have not been confirmed so far. There is no evidence that the lion has been sighted there,” the mayor added.
Meanwhile, experts have said the escaped animal may be sleeping in one of the area’s many woods.