LOS ANGELES (Reuters) - Officials in a Southern California city are trying to identify an animal caught in grainy black-and-white video footage moving quietly through a residential neighborhood, saying the beast does not appear to be a dog or a mountain lion.

The creature was captured on a resident's security camera in the early morning hours last Friday, walking calmly past parked cars in the Los Angeles suburb of Norwalk and was initially thought to be a mountain lion, according to the city's Facebook page.

But in a subsequent post city officials quoted an expert with the California Department of Fish and Wildlife who concluded the four-legged intruder was not a mountain lion. That same expert could not identify the animal further.

Meanwhile Craig Packer, a professor at the University of Minnesota's Lion Research Center, agreed in an interview with the Los Angeles Times that the beast was not likely a mountain lion or cougar, adding that he thought it resembled an African lion.

A San Diego Zoo spokeswoman said it appeared to be a big cat of undetermined origin, possibly "some kind of hybrid."

Despite stepped-up patrols by authorities the creature has not been seen since it was videotaped last week but the city has cautioned residents to contact law enforcement immediately if they run across it.

(Reporting by Dan Whitcomb; Editing by Eric Beech)