At least four alligators have been seen in northern US cities in recent weeks, far from their usual southern habitat.

Analysts said the beasts were abandoned pets, not global warming refugees.

"People buy them as pets and then they get too big and at some point they decide they just can't deal with it," said Kent Vliet, a University of Florida alligator expert.

The reptiles have turned up in a Chicago river, a New York City street and a Massachusetts town this month.

On Sunday, an off-duty firefighter discovered a three-foot (0.9m) alligator sauntering across an avenue in Brockton, Massachusetts. It was wearing a spiked collar and dragging a broken leash.

If humans keep on encroaching on the natural habitat of wildlife, where else is the wildlife supposed to go?

Mark

Reminds me of a late 70s or early 80s B-budget horror called Alligator. Boy wins baby alligator at a Fair, flushes it down toilet, and many years later it terrorises LA.

Should be more worried about the African bee colonies and the pythons moving north...

Reminds me of a late 70s or early 80s B-budget horror called Alligator. Boy wins baby alligator at a Fair, flushes it down toilet, and many years later it terrorises LA.