Milwaukee police have closed off various sections of the city as the "Milwaukee Lion" mystery continues.

Officials are still unsure about what kind of animal has been spotted over the last week wandering through densely populated areas of the city, sitting under bridges, darting down hills and casually slinking past parked cars and small bungalows.

Some speculate that it could be a young African lion that was purchased on the open market, kept as a pet and then released when it became too large to handle. While others believe that it could be a cougar, an animal that has been spotted more frequently in populated areas of the Midwest in recent years, according to the New York Times.

Adding to the mystery, the Milwaukee County Zoo has counted all of its lions and has assured the public that they are all accounted for, according to the Daily Mail.

The creature, now dubbed the Milwaukee Lion, has captivated the 600,000 people of Milwaukee in a mix of amusement and fear. However, police are taking the case very seriously as calls about sightings continue to pour in.

The latest call came from Herbet Ball who spotted the cat near Lincoln Creek Saturday, sparking a huge police response over the weekend.

"She was walking down the hill sideways, putting her feet crossways," he said Monday, according to the Chicago Tribune. "She was snooping down with her head, like she was fixing to attack somebody. The people over there were having a cookout... and I ran over there to tell them there's a cat coming their way. But what the cat did is change her mind—she went under the bridge and relaxed."

Ball called police and they soon swarmed the neighborhood, posting rifle-wielding officers on the bridge and sending others to beat the bushes in hopes of flushing out the animal. Two officers said they briefly saw the cat, but it managed to escape.

Police aren't expecting to receive too many clues about the identity of the animal.

Jeff Kozlowski, owner of the Wisconsin Big Cat Rescue in Rock Springs, Wis., said that if the cat had been an exotic pet, there was little hope of finding the person who lost control of the animal.

"If you had a pet lion and it got out and it was causing this much uproar," he said dryly, "would you call in and say it was yours?"