BERLIN -- A German man taking his regular morning stroll was killed by an elephant who had escaped from a nearby circus, police said Saturday.

The 65-year-old man was walking in the woods near Buchen, a town in southwest Germany, when the African elephant attacked him shortly after 5 a.m., said Heidelberg police spokeswoman Yvonne Schmierer. She declined to say what injuries the unnamed man suffered.

The 34-year-old female elephant, called 'Baby,' was captured and returned to the circus. Police are now investigating whether someone let the elephant out of its secure enclosure, and why the animal acted aggressively toward the man.

"There's evidence of third party involvement," said Schmierer. "Either someone forgot to shut the enclosure, or the elephant was released intentionally."

German news agency dpa reported that the elephant had previously injured people. It quoted a representative of the German branch of animal rights group PETA calling for authorities to take the elephant away from the circus.