A presumed lioness is on the loose in Berlin, where residents in some areas have been warned to stay indoors as scores of police try to track down the animal.

Police, who believe the animal is an escaped pet, were alerted about midnight on Wednesday (local time) by two people who recorded mobile phone footage of what appeared to be a wild boar and a lion chasing each other.

No boar carcass has been found.

“Even experienced officers had to conclude that it was probably a lioness,” a police spokesperson told local broadcaster RBB.

Authorities believe the wild cat could sleeping in one of the many lakeland forests in Brandenburg, the state that surrounds Germany’s capital.

“We recommend that people shouldn’t leave the house to walk and especially not to go jogging in the forest,” said Michael Gruber, mayor of Kleinmachnow, a municipality on Berlin’s south-western border where the animal was first spotted.

An operation to track it down using two helicopters, drones and infrared cameras was expanded early on Thursday (local time), as 100 police officers joined forces with hunters and vets.

They would aim to tranquilise and capture the animal and only kill her if she posed a danger to people, Mr Gruber said, adding that the search was now concentrated in the municipality’s north-eastern part.

As no zoos or circuses have reported a missing lioness, police believe she must be an escaped pet.

Animal rights groups criticised successive governments for failing to ban the practice of keeping wild animals as pets.

“Over the past two decades there have been repeated cases of big cats escaping from homes and circuses,” said Peter Hoeffken of rights group PETA.

“Despite countless warnings, politicians have failed to ban the keeping of exotic wildlife.”

Circus keeper Michel Ramon Rogall told Reuters there was no circus with wild animals on the road in eastern Germany, “and they wouldn’t escape either [if there was]”.

-Reuters