Germany: Suspected lioness on the loose outside Berlin, residents urged to stay indoor (VIDEO)

A "loose, dangerous animal," suspected to be an escaped big cat, was reportedly sighted in a Potsdam region on the fringes of the German capital on Thursday, police said.

Authorities are using helicopters to track what they believe is a female lion and have called on residents to stay indoors, the rbb public broadcaster reported.

Police said veterinary specialists and hunters were also taking part in the operation to find the animal.

What do we know so far?

Residents have reportedly received messages via warning apps. Among other things, they have been requested not to go for walks in the woods and to seek shelter in their houses or cars if they sight the animal.

They said they did not know where the animal may have come from, having checked with zoos, circuses and animal shelters who all said they were not missing a lioness.

The search for the suspected lioness is centered on the municipality of Kleinmachnow at the southern edge of Berlin. The municipality has some 20,000 residents.