BELLE VERNON, Pa. (AP) - Authorities are investigating an unconfirmed sighting of an alligator in the Monongahela River in southwestern Pennsylvania.


The Southwest Regional police department said a resident reported seeing a 6- to 7-foot alligator swimming upstream in the river in Belle Vernon, Fayette County at about midnight Tuesday.


Police said investigators determined that the animal may have been seen at about 2 p.m. Tuesday, when a Brownsville man watching ducks in the river reported that "something took one of the ducks down - the whole duck."


Police chief John Hartman said volunteer firefighters and the Coast Guard searched Wednesday. Police are also seeking help from the Fish and Boat Commission and the Pittsburgh Zoo.


Hartman said four similar sightings have been reported in the region since 2007.


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