Police are investigating who might have decapitated scores of animals and drained them of their blood in a west German city, a spokesman said Thursday.

Over the past year the corpses of 21 rabbits, three chickens and four wild birds have been found headless in and around the city of Bochum, police spokesman Volker Schuette said.

Police have formed a special commission to investigate the grisly discoveries, but so far have no clues about who may have killed the animals.

"There is a person out there who urgently needs to be arrested," Schuette said, describing the acts as "very disturbing."

Police urged people with information to come forward, saying the suspect may have been seen smeared with blood because he or she would drain the animals' blood and take their heads.

In one case, two rabbits were decapitated while three others were taken from the same pen in a person's yard. The next day, another rabbit was decapitated and left in the same pen.

"That was naturally particularly awful for the owner — to know that the suspect was back a day later on their property," Schuette said.