LONDON — Somewhere in England, there may be a lion on the loose.

Police in the English county of Essex say they've deployed armed officers, heat-seeking helicopters, and tranquilizer-armed experts from the local zoo a hunt for a lion after a member of the public reported spotting a big cat ambling through a field.

Where the beast might have come from is a mystery. The zoo's animals have been accounted for and police say that a local circus is not missing any such animals.

But officers said Monday that they don't believe the sighting is a hoax and have advised residents to be on their guard.

The sighting prompted a media frenzy in Britain, with the Daily Mail tabloid splashing a picture of a snarling lion across its front page.