German police urged residents of Berlin's southern suburbs to stay indoors Thursday, as they scoured the area for a wild animal on the loose, apparently a lioness.

Police first issued the alarm in the early morning hours, after two people saw what appeared to be a lioness chasing a wild boar down a street less than five kilometers from the German capital.

"Around midnight, we received a message hard to imagine. Two passersby who saw one animal chasing another," Daniel Keip, Brandenburg police spokesman, told RBB radio.

"One was a wild boar and the other apparently a wild animal, a lioness. The two men recorded a video on their phones and even experienced policemen had to concede that it was probably a lioness," he said.

Berlin police then alerted the public to the beast's presence, initially putting the southwestern suburbs on alert and then expanding the area of the search.

As authorities, backed by several helicopters, scoured the area around the communities of Kleinmachnow, Teltow and Stahnsdorf at the start of the workday, according to local media, police urged residents to stay indoors.

"The wild animal that escaped has not yet been found!" the police of Brandenburg, the region around Berlin, wrote on Twitter around 7:30 am. "We ask you not to leave your houses."

Pets should also remain indoors, the tweet added.

It remains unclear where the feline could have come from.

"No animal parks, zoos or circuses are missing an animal of this kind," the police spokesman told RBB.

Dozens of officers were combing through the area, with drones searching from above.

A veterinarian and two hunters have also joined the search.

A spokeswoman for the Kleinmachnow municipality told RBB that daycare centers had been told to keep children inside, and vendors at a local market were asked not to set up their stalls.

"There are hardly any people out," said the spokeswoman.